NAS Drive Price Per Terabyte Chart
Cost per terabyte is the only figure that makes NAS drives of different capacities comparable, and no retailer prints it. The best value per terabyte in this table is the WD Red Plus 8TB NAS HDD (WD80EFPX), and the most expensive costs 1.4 times as much per terabyte for storage that behaves identically.
Cost per terabyte is the number that decides a drive purchase, and it is the one figure no retailer puts on the page. A small drive priced next to a large one tells you nothing useful. Divided by capacity they become directly comparable, and the answer is often the reverse of what the sticker price suggests.
Every figure below is computed from the verified catalog price and the drive's stated capacity, shown as a budget tier and a rounded-up cost per terabyte, not typed in, so the table cannot drift away from the underlying product data. Any drive whose price or capacity could not be read cleanly is left out rather than estimated.
What is the cheapest NAS drive per terabyte?
| Drive | Capacity | Budget | Per TB vs lowest | 8-bay full |
|---|---|---|---|---|
| WD Red Plus 8TB NAS HDD (WD80EFPX) | 8 TB | Under $500 | Lowest | Under $3,000 |
| WD Red Pro 20TB NAS HDD (WD202KFGX) | 20 TB | Under $1,000 | +5% | Under $7,500 |
| Seagate IronWolf Pro 12TB NAS HDD (ST12000NE0008) | 12 TB | Under $500 | +5% | Under $4,000 |
| Seagate IronWolf 4TB NAS HDD (ST4000VN008) | 4 TB | Under $250 | +20% | Under $2,000 |
| WD Red Plus 6TB NAS HDD (256 MB cache) | 6 TB | Under $500 | +40% | Under $3,000 |
The last column is the part people underestimate: filling eight bays multiplies the drive decision by eight. A $30 per terabyte difference becomes hundreds of dollars across a full chassis, which is why this table is worth more attention than the enclosure comparison.
<!-- gift-guides-xlink -->Which capacity band is the sweet spot?
Cost per terabyte falls as capacity rises, but not evenly. Averaging within bands shows where the curve flattens, and that is the point where paying for more capacity stops buying you cheaper storage.
| Capacity band | Drives listed | Average per TB vs lowest band |
|---|---|---|
| 2 to 6 TB | 2 | +25% |
| 8 to 12 TB | 2 | Lowest |
| 20 TB and up | 1 | Lowest |
Why fewer large drives usually beats more small ones
Three reasons, and one real counter-argument. Larger drives are cheaper per terabyte, they draw less power per terabyte, and they leave empty bays so you can expand later without replacing anything. Against that: a larger drive takes proportionally longer to rebuild after a failure, and the rebuild window is exactly when a second failure destroys the array.
That is an argument for more parity, not for smaller drives. If large drives make you nervous about rebuild time, the fix is RAID 6 or RAIDZ2 rather than a chassis full of 4 TB disks. The rebuild time chart shows how long the exposure actually lasts, and the RAID capacity calculator will show what each layout costs you in usable space.
What about SSDs?
Still several times the cost per terabyte of spinning disk, which is why the sensible pattern is a small SSD for cache or applications alongside hard drives for bulk capacity. SSDs earn their premium where random access matters, and for most home servers that is the app volume rather than the media library.
| SSD | Capacity | Budget | Per TB vs lowest SSD |
|---|---|---|---|
| Samsung 870 EVO 2TB SATA SSD | 2 TB | Under $500 | Lowest |
| WD Red SA500 2TB NAS SSD (M.2 2280) | 2 TB | Under $500 | +5% |
| Samsung 870 EVO 1TB SATA SSD | 1 TB | Under $500 | +35% |
The budgeting mistake almost everyone makes
People budget for the NAS and treat drives as an afterthought. It is the wrong way round. An eight bay enclosure runs perhaps $600 to $1,000; filling it with eight drives at $200 to $500 each runs $1,600 to $4,000. The drives are the purchase, and the enclosure is the accessory.
This also means drive choice compounds. Buying one capacity tier up costs a little now and saves an entire migration later, because the alternative to expanding is replacing every drive in the array one at a time and rebuilding between each. Our migration guide covers what that actually involves, and it is a strong argument for buying larger the first time.
Prices move constantly and drive pricing is unusually volatile, so treat every tier here as a snapshot for comparison rather than a quote. Amazon shows the current price.
Related
- Best NAS hard drives, picked by tier rather than by price alone
- RAID rebuild time chart, the risk side of large drives
- Usable capacity by RAID level
- TB versus TiB, why your drives look smaller than the box said
- RAID capacity calculator, cross-vendor
Frequently asked questions
What is a good price per terabyte for a NAS drive?
Anything under $40 per terabyte is competitive for a NAS rated drive at the time of writing. Cost per terabyte falls as capacity rises, so the cheapest per terabyte figure almost always belongs to a large drive rather than a small one. Compare within a capacity band rather than across the whole table, because a 4 TB drive will essentially never beat a 16 TB drive on this metric.
Why is cost per terabyte the number that matters?
Because it is the only figure that makes drives of different capacities comparable, and it is the one retailers never print. A 4 TB drive and a 20 TB drive priced side by side tell you nothing on their own. Divided by capacity they become directly comparable, and the answer is frequently the opposite of what the sticker price suggests: the expensive drive is often the cheaper storage.
Should I buy fewer large drives or more small ones?
Fewer, larger drives, in almost every case. Larger drives are cheaper per terabyte, draw less power per terabyte, and leave empty bays for expansion later. The counter-argument is rebuild risk: a larger drive takes longer to rebuild after a failure, which widens the window in which a second failure kills the array. That is an argument for RAID 6 or RAIDZ2 rather than for buying small drives.
Are SSDs worth it for NAS storage yet?
Not for bulk storage. SSD cost per terabyte still runs several times that of spinning disks, so the sensible pattern is a small SSD for cache or apps alongside HDDs for capacity. SSDs earn their price where random access matters, which for most home servers is the app volume rather than the media library.
Does shucking external drives actually save money?
Often yes, sometimes substantially, because external enclosures are sold at promotional pricing that bare drives are not. The costs are real though: shucking usually voids the drive warranty, some shucked drives use 3.3 volt pin logic that needs taping or an adapter, and the drive inside is not always the model people expect. Treat the saving as real and the warranty as gone.
How much should I budget for drives versus the enclosure?
Expect the drives to cost more than the NAS, often several times more. An eight bay build with eight drives at $200 to $500 each is $1,600 to $4,000 of drives against a $600 to $1,000 enclosure. That ratio is the single most common budgeting mistake in this niche, and it is why drive selection deserves more attention than enclosure selection.
How we choose: we compare published manufacturer specifications, drive datasheets, published reliability statistics and verified owner reviews. We do not test hardware in person, and we are not tied to any NAS vendor. Capacity and power figures here are researched guidance, not a warranty. RAID protects against drive failure, not against deletion, ransomware, fire or theft, so keep verified backups regardless of what any calculator tells you.
