4-Bay NAS Deals UK – Prime Big Deal Days 2026
Prices checked
Prime Big Deal Days runs 6 to 7 October 2026 for Prime members, with new Today's Big Deals three times a day. We re-check these prices at 08:00, 16:00 and 21:00 UK time.
As an Amazon Associate we earn from qualifying purchases. Prices and availability come from Amazon.co.uk as of the last update and may change.
What is genuinely cheap here today: the UGREEN DH4300 Plus at £279.99 (£70.00/bay), at or below the lowest price we have recorded for it (£313.99 on 23 Jul 2026). 5 of 9 products in the table are at or near their own recorded low; the rest only beat Amazon's reference price or are new to our tracker.
Four bays is where a NAS starts to make sense for a growing media library: RAID 5 gives three drives of space with one-disk protection, or RAID 6 survives two failures. This page covers the DH4300 Plus, DXP4800 Plus and GT, the F4-425 Plus and F4-424 Pro, the TS-464 and the DS925+. Prices are shown per bay, and the fill table builds each one out with today's cheapest drives.
Today's prices, judged against our own records
| Product | Bays | Price | Amazon was | Value | Our recorded low | Verdict | |
|---|---|---|---|---|---|---|---|
| UGREEN DH4300 PlusPrime deal checked 6 Oct 2026 | 4 bays | £279.99 | £70.00/bay | £313.9923 Jul 2026 | Real low | Buy on Amazon | |
| TerraMaster F4-425Prime deal checked 6 Oct 2026 | 4 bays | £299.99 | £75.00/bay | £399.9922 Jul 2026 | Real low | Buy on Amazon | |
| UGREEN DXP4800 PlusPrime deal checked 6 Oct 2026 | 4 bays | £469.99 | £117.50/bay | £526.9923 Jul 2026 | Real low | Buy on Amazon | |
| UGREEN DXP4800 GTPrime deal checked 6 Oct 2026 | 4 bays | £469.99 | £117.50/bay | £589.9926 Jul 2026 | Real low | Buy on Amazon | |
| TerraMaster F4-424 ProPrime deal checked 7 Oct 2026 | 4 bays | £529.29 | £132.32/bay | £592.4923 Jul 2026 | Real low | Buy on Amazon | |
| TerraMaster F4-425 PlusPrime deal checked 7 Oct 2026 | 4 bays | £351.99 | £88.00/bay | None yet | No history yet | Buy on Amazon | |
| Synology DS925+Prime checked 7 Oct 2026 | 4 bays | £705.24 | £176.31/bay | None yet | No history yet | Buy on Amazon | |
| QNAP TS-464Prime checked 7 Oct 2026 | 4 bays | £709.20 | £177.30/bay | None yet | No history yet | Buy on Amazon | |
| Synology DS923+Prime checked 31 Jul 2026 | 4 bays | £618.53 | £154.63/bay | Awaiting recheck | Not rechecked yet | Buy on Amazon |
Out of stock on Amazon.co.uk at our last check: Synology DS425+.
Verdicts compare today's price with the lowest price we have recorded for the same listing. Amazon was is Amazon's own reference price. Prices can change after our check; the price on Amazon.co.uk at checkout applies.
Is it really a deal?
We rate each four-bay unit against its own logged prices, then show the total with four drives so a cheap box with expensive limits stands out. 5 of 9 products we have re-priced are at or within 3% of their lowest recorded price; the UGREEN DH4300 Plus is 11% under our recorded low of £313.99, logged on 23 Jul 2026. 1 sit above what we have recorded, such as the QNAP TS-433, now 6% above our recorded low; those are in the collapsed list at the bottom. 1 price is from an earlier check and is listed with its check date but not judged until we re-price it. 3 are too new to our tracker to measure, so for those we show Amazon's own was-price as Amazon's claim, and the fill-cost table below is the better guide to value.
Cheapest full build for each unit
For each enclosure on this page, the drive size that gives the lowest cost per usable terabyte at today's prices.
| Build | Enclosure | Drives | Total | Usable | £ per usable TB | |
|---|---|---|---|---|---|---|
| UGREEN DH4300 Plus+ 4 x WD Red Pro 22TB Real low | £279.99 | £1,460.00 | £1,739.99 | 60.0TB RAID 540.0TB RAID 6 | £28.99 | Buy Now |
| TerraMaster F4-425+ 4 x WD Red Pro 22TB Real low | £299.99 | £1,460.00 | £1,759.99 | 60.0TB RAID 540.0TB RAID 6 | £29.32 | Buy Now |
| TerraMaster F4-425 Plus+ 4 x WD Red Pro 22TB Real low | £351.99 | £1,460.00 | £1,811.99 | 60.0TB RAID 540.0TB RAID 6 | £30.19 | Buy Now |
| UGREEN DXP4800 Plus+ 4 x WD Red Pro 22TB Real low | £469.99 | £1,460.00 | £1,929.99 | 60.0TB RAID 540.0TB RAID 6 | £32.15 | Buy Now |
| UGREEN DXP4800 GT+ 4 x WD Red Pro 22TB Real low | £469.99 | £1,460.00 | £1,929.99 | 60.0TB RAID 540.0TB RAID 6 | £32.15 | Buy Now |
| TerraMaster F4-424 Pro+ 4 x WD Red Pro 22TB Real low | £529.29 | £1,460.00 | £1,989.29 | 60.0TB RAID 540.0TB RAID 6 | £33.14 | Buy Now |
| Synology DS925++ 4 x WD Red Pro 22TB Real low | £705.24 | £1,460.00 | £2,165.24 | 60.0TB RAID 540.0TB RAID 6 | £36.07 | Buy Now |
| QNAP TS-464+ 4 x WD Red Pro 22TB Real low | £709.20 | £1,460.00 | £2,169.20 | 60.0TB RAID 540.0TB RAID 6 | £36.14 | Buy Now |
Usable space uses the same maths as our RAID calculator, after about 9% formatting overhead. Drive prices are the cheapest in-stock NAS-rated CMR drive at each size when we last checked. Buy Now adds the enclosure and all the drives to your Amazon.co.uk basket in one go.
Prices we checked and would not pay (1)
These are above the lowest price we have recorded for the same listing, or above their 30-day median. They are here so you can see we checked them.
| Product | Bays | Price | Amazon was | Value | Our recorded low | Verdict | |
|---|---|---|---|---|---|---|---|
| QNAP TS-433 checked 6 Oct 2026 | 4 bays | £428.00 | £107.00/bay | £402.0023 Jul 2026 | Above our low | Buy on Amazon |
Frequently asked questions
RAID 5 or RAID 6 on four bays?
RAID 5 gives you three drives of usable space and survives one failure. RAID 6 halves usable space on four bays but survives two, which matters with large drives that take a day or more to rebuild.
Can I start a four-bay NAS with two drives?
Yes. Start with a mirror and expand later, though changing RAID level can take many hours. Synology SHR makes adding mismatched drives easier than plain RAID.
Which four-bay NAS is best for Plex?
The Intel models with Quick Sync, such as the DXP4800 Plus, F4-424 Pro and TS-464, handle 4K transcoding. The ARM-based DH4300 Plus suits direct play only.
Is the cheapest four-bay NAS the best value?
Not always. Compare the full build in the fill table: memory you cannot upgrade or slow networking can cost more later than a higher enclosure price today.
Related
- Best 4-Bay NAS UK 2026: Top Picks for Home Storage
- NAS by Bay Size 2026: 2-Bay vs 4-Bay vs 5-Bay UK
- NAS RAID Calculator 2026: SHR, RAID 5/6 Capacity
- Best NAS Under £500 UK 2026: Top Picks Ranked
- 2-Bay NAS Deals UK – Prime Big Deal Days 2026
- 6 & 8-Bay NAS Deals UK – Prime Big Deal Days 2026
- UGREEN DXP4800 Plus Deals UK – Prime Big Deal Days 2026
- All Prime Big Deal Days NAS and drive deals