A NAS is two purchases pretending to be one: the enclosure, and the drives that usually cost more than it. This tool prices both sides live — pick a bay count, RAID level and drive capacity, and every in-stock enclosure is ranked as a complete build by what actually matters: total cost per usable terabyte after RAID overhead.
| Enclosure | Network | Enclosure $ | 4 drives | Build total | $/usable TB | Buy |
|---|---|---|---|---|---|---|
TerraMaster F4-425 4-Bay TOS 6 | — | $365 | $1,240 | $1,605 | $27 | Buy |
Synology DiskStation DS423 4-Bay Diskless DSM 7 | 2x 1GbE | $400 | $1,240 | $1,640 | $27 | Buy |
TerraMaster F4-425 Plus 4-Bay TOS 6 | — | $520 | $1,240 | $1,760 | $29 | Buy |
Synology DiskStation DS425+ 4-Bay Diskless DSM 7 | 2.5GbE | $600 | $1,240 | $1,840 | $31 | Buy |
UGREEN NASync DXP4800 Plus 4-Bay UGOS Pro | 10GbE + 2.5GbE | $620 | $1,240 | $1,860 | $31 | Buy |
Synology DiskStation DS925+ 4-Bay DSM 7 | 2x 2.5GbE | $631 | $1,240 | $1,871 | $31 | Buy |
QNAP TS-464-8G 4-Bay QTS 5 | 2x 2.5GbE | $639 | $1,240 | $1,879 | $31 | Buy |
UniFi UNAS Pro 4 4-Bay UniFi Drive | — | $649 | $1,240 | $1,889 | $31 | Buy |
UGREEN NASync DXP4800 Pro 4-Bay UGOS Pro | — | $680 | $1,240 | $1,920 | $32 | Buy |
Asustor Lockerstor 4 Gen2+ AS6704T 4-Bay ADM | 2x 5GbE | $682 | $1,240 | $1,922 | $32 | Buy |
TerraMaster F4-424 Pro 4-Bay TOS 6 | 2x 2.5GbE | $688 | $1,240 | $1,928 | $32 | Buy |
Drive pricing uses the single cheapest in-stock 20TB drive across new and refurbished channels; enclosures are the cheapest in-stock offer per model. Out-of-stock hardware never appears. Prices refresh every 2 hours.
Start from your data, not from hardware. Estimate what you store today, multiply by your three-year growth, and add half again for safety — that number is the usable capacity to aim for. Then work the builder backwards: at four bays in RAID 5, usable capacity is three drives' worth, so 45TB of need means 16TB-class drives or better; at six bays in RAID 6 the same need fits comfortably on 12TB drives, often cheaper per usable terabyte despite the extra spindles. The tool makes those trades visible instead of theoretical, because every combination is priced from the same live market data.
Watch how the ranking shifts as you change inputs. At small capacities the enclosure dominates the total and TerraMaster's budget boxes win everything; as drive capacity climbs, the enclosure fades into the noise and the ranking converges — at which point paying for UGREEN's 10GbE or Synology's DSM costs only a few dollars per usable terabyte more. That convergence is the most useful thing this tool teaches: the bigger your build, the cheaper the premium features become in relative terms.
Two companion tools complete the workflow: the RAID planner models fault tolerance and rebuild exposure for the array you are about to buy, and if you are replacing an existing NAS, the upgrade planner nets out what your current drives are worth on the used market — in the current shortage, often enough to change the decision. Drive-side detail lives on the NAS drive tracker and the recertified rankings.
The household archive. Two bays, RAID 1, one mid-size drive capacity — the configuration for a family that wants photos, documents and computer backups protected without thinking about storage again for years. Run this in the builder and the enclosure choice barely moves the total; what moves it is drive capacity, which is why the right question is not "which NAS" but "how many terabytes will this family produce by 2029." Overshoot deliberately: a mirror cannot borrow space later, and the marginal terabyte is cheapest at purchase time. Then pair the build with one external drive for offline snapshots, which no RAID level replaces.
The media library. Four bays, RAID 5, large drives — the configuration most of this site's readers actually build. The builder's ranking here is a live referendum on the brand premiums: the budget enclosures win the total, the 10GbE and Intel-iGPU models cost a few dollars more per usable terabyte, and whether that premium is worth it depends entirely on whether the library gets transcoded and how fast your network moves a 60GB remux. Toggle between capacities and watch the per-terabyte figure — the capacity tier where it bottoms out is this week's sweet spot, and it shifts with the shortage market.
The consolidation. Six or eight bays, RAID 6, enterprise-class drives — the build for replacing several aging boxes with one array that will outlive them all. Here the builder teaches its sharpest lesson: at full population the drives dwarf the enclosure so thoroughly that the premium for dual 10GbE or ECC memory amortizes to noise, while the difference between drive capacities compounds into hundreds of dollars. Run it both ways — eight mid-size drives versus six large ones — and note that the large-drive path leaves bays empty, which is future expansion the mid-size path spends today.
Drive pricing does not scale linearly with capacity — the market always has a tier where dollars per terabyte bottoms out, with a premium above it for density and a penalty below it for obsolescence. In the current shortage that curve moves week to week, which is why the builder recalculates rather than recommends. The technique: hold your bay count and RAID level fixed, then step through drive capacities and watch the per-usable-terabyte figure. Where it bottoms out is the market's current sweet spot; whether you buy there or one tier above depends on how much you value deferring your next upgrade. Buying above the sweet spot costs a known premium today; buying below it usually costs more later, because small drives consume bays — the one resource a chassis can never grow.
The refurbished toggle happens automatically: whenever a recertified enterprise drive undercuts new stock at a capacity, the builder uses it and says so. In practice this is where the shortage market's best value hides — datacenter pulls with tested hardware at prices new drives cannot meet — and the recertified rankings carry the full context on warranties and what to verify on arrival.
A note on timing in the current market: shortage pricing rewards patience unevenly. Enclosure prices have been broadly stable, but drive prices swing enough that running the same build a week apart can move the total by a meaningful percentage. If your build is not urgent, configure it here, note the per-usable-terabyte figure, and check back across a few refresh cycles — the price forecast tracks the direction of travel, and buying the drives on a dip while ordering the enclosure whenever is the pattern that consistently beats buying everything in one impatient afternoon.
Amazon is full of bundle listings — enclosures pre-filled with drives at a single price — and we deliberately exclude every one of them from this site. The bundle price hides both halves of the deal: you cannot see whether the enclosure is discounted or marked up, the included drives are frequently models you would not choose (and sometimes SMR), and the bundle locks you out of the recertified market where the real per-terabyte value lives. Pricing the build yourself, with this tool, has consistently beaten the bundles we have audited — and it leaves you knowing exactly what hardware you own, which matters the day a drive needs replacing.
Enclosure prices are the cheapest in-stock offer for each verified diskless model in our NAS device database; drive prices are the single cheapest in-stock drive at each capacity across new and refurbished channels, labeled accordingly. Both sides refresh every two hours from Amazon US via the Creators API — the same pipeline behind every tracker on this site — and out-of-stock hardware drops out of the tool rather than lingering at a stale price. Usable capacity follows standard RAID arithmetic: mirrored pairs for RAID 1, one parity drive for RAID 5, two for RAID 6, everything for JBOD. The tool deliberately excludes drive bundles, taxes, and network upgrades; it prices the storage, and the storage only.
The complete cost of a working NAS: the enclosure plus the drives to fill it, divided by the usable capacity your chosen RAID level actually delivers. Every number is live — enclosures from our NAS device tracker, drives from our per-capacity price ladder — so the ranking reflects today's market, not a stale guide. The output metric that matters is dollars per usable terabyte, which is the only fair way to compare a cheap enclosure with expensive drives against the reverse.
Because RAID overhead and enclosure pricing interact. A six-bay running RAID 6 gives up two drives to parity; a four-bay in RAID 5 gives up one; a mirror gives up half. Dividing the total build cost by post-RAID usable capacity puts every configuration on one axis. Sticker prices reward the wrong choices — usable-terabyte pricing rewards the build that stores your data cheapest with the protection level you chose.
Not necessarily. Starting a six- or eight-bay half-populated in RAID 6 and expanding as prices dip is often the best-value path in the current shortage — you get the fault-tolerance structure now and buy capacity on your schedule. The builder prices full population because that is the comparable number across enclosures; treat it as the ceiling, not a mandate.
The builder automatically uses whichever is cheaper at each capacity and labels it. Refurbished datacenter pulls routinely beat new NAS drives per terabyte with enterprise-grade hardware — the honest trade is a shorter reseller warranty. For RAID 6 builds with a backup, refurb is a rational default; for a 2-bay mirror holding your only copy, pay for new.
No — no cables (included with enclosures), no switch upgrades, no backup target. If you are moving to 10GbE, budget the switch and NICs separately. And remember RAID is not a backup: a complete plan includes a second copy of the irreplaceable subset, which for most households is far smaller than the array itself.
Only live in-stock prices appear — if no drive at a capacity or no enclosure at a bay count currently verifies in stock, the option drops out rather than showing a stale or fabricated number. Check back after the next 2-hour refresh, or pick the nearest available configuration.