Pick a model and see the lowest current prices on eBay, the biggest second-hand NAS market. A NAS is a good used buy because the enclosure barely wears out, but two things decide whether a cheap one is a bargain or a headache: how much life is left in the drives, and how long the maker will keep issuing software updates for that model. Both are worth more than a few dollars off the price.
Live from eBayEvery model ranked by price per drive bay, using today's cheapest live listing. It is the fairest way to compare, because the headline price mostly reflects how many bays you get: a two-bay unit can look cheap and still cost five times as much per bay as a four-bay one. Lower is more storage capacity for your money. Two things this number does not capture, so check both before you buy: whether the model still gets software updates, and that drives are extra unless the listing says otherwise. Tap a model to see its listings.
| NAS | Cheapest now | 5-day | Bays | $ / bay |
|---|---|---|---|---|
| $110 | flat | 4-bay | $28 best value | |
| $290 | flat | 5-bay | $58 | |
| $480 | flat | 8-bay | $60 | |
| $275 | flat | 4-bay | $69 | |
| $142 | flat | 2-bay | $71 | |
| $293 | flat | 4-bay | $73 | |
| $180 | flat | 2-bay | $90 | |
| $180 | flat | 2-bay | $90 | |
| $400 | flat | 4-bay | $100 | |
| $485 | flat | 4-bay | $121 | |
| $529 | ▲341% | 4-bay | $132 | |
| $299 | flat | 2-bay | $150 | |
| $600 | flat | 4-bay | $150 |
The drives matter more than the box. Most used units sell diskless, which is normal and usually what you want. Where drives are included, treat them as a bonus and not as value: a disk that has been spinning in someone's cupboard for five years is the part most likely to fail, and nothing in a listing photo tells you how tired it is. If the seller can read you the power-on hours from the drive health page, that is worth more than a discount.
Check the software support window before you check the price. Synology and QNAP drop older models from current DSM and QTS releases, and once that happens you stop getting security patches on a device that holds your files and sits on your network. A three-year-old model in support is a far better buy than a six-year-old one that has aged out, whatever the saving. Look up the specific model number, not the family.
Bays are cheap, filling them is not. A two-bay unit like the DS220+ or DS224+ covers backups and media for most households, runs quiet, and is the sweet spot second-hand. Four-bay models are worth it if you genuinely need the capacity or want to run containers and virtual machines, but remember every extra bay is another drive you have to buy, and drives usually cost more than the enclosure did.
Confirm the power adapter is included. These use proprietary bricks, and tracking down the right one for an older model is more annoying and more expensive than it sounds. Also ask that the unit has been reset and the previous owner's account removed, so you are not inheriting someone else's shares and users.
Live eBay listings, the biggest second-hand NAS market. Pick a model and it fetches the current cheapest genuine unit, filtering out empty enclosures, drive caddies, trays and spare power supplies that would otherwise look like a cheap NAS.
Usually not, and that is the single biggest thing to check. Most used NAS units sell diskless, which is normal and fine. Where a listing does include drives, treat them as a bonus rather than value: second-hand drives with years of spinning behind them are the part most likely to fail, and you cannot tell from a photo.
For most people a two-bay Synology such as the DS220+ or DS224+ is the sweet spot: cheap second-hand, quiet, and enough for backups and media. Step up to a four-bay (DS920+, DS923+, QNAP TS-464) only if you actually need the capacity or want to run containers and virtual machines, because the extra bays cost real money once you fill them with drives.
Ask the seller for the drive health hours if disks are included, confirm the power adapter is in the box because proprietary ones are annoying to replace, and check the model is still receiving software updates. Older units get dropped from the current DSM or QTS release, which eventually means no security patches, and that matters on a device holding your files.
A daily snapshot of the lowest genuine eBay price for every model we track, and how good that price is right now versus its usual level, updated automatically. Prices last refreshed 1 August 2026 . Tap a model above for the full live list.
| Model | Cheapest now | vs typical | This week |
|---|---|---|---|
| Synology DS415+ | $110 | – | steady |
| QNAP TS-251+ | $142 | – | steady |
| Synology DS220j | $180 | – | steady |
| Synology DS218+ | $180 | – | steady |
| Synology DS916+ | $275 | – | steady |
| Synology DS1513+ | $290 | – | steady |
| Synology DS418 | $293 | – | steady |
| Synology DS220+ | $299 | – | steady |
| Synology DS918+ | $400 | – | steady |
| Synology DS1815+ | $480 | – | steady |
| Synology DS920+ | $485 | – | steady |
| QNAP TS-451+ | $529 | – | ▲ 341% |
| QNAP TS-464 | $600 | – | steady |