When you're building a Plex server, a large-scale NAS, or a backup vault, the price per terabyte becomes the single most important metric. In February 2026, the "sweet spot" for value has shifted towards high-density enterprise drives.
The Rise of the 18TB+ Standard
A few years ago, 8TB was the king of value. Today, the manufacturing economics have scaled. 18TB and 20TB drives often have lower power-on overhead and better per-slot efficiency. In the UK market, these larger drives are now regularly appearing on eBay as data centres cycle through their hardware.
🏆 Top Pick for UK Value: Seagate Exos X18
The **Seagate Exos X18** (specifically the 18TB model) is currently the most popular choice for UK home labs. It offers 7200RPM performance, a helium-sealed design, and a massive 550TB/year workload rating.
- New Price: £300 - £350
- Refurb Price: £180 - £220
- Best For: RAID 6 arrays, bulky media storage.
WD Gold vs WD Red Pro
Western Digital's lineup can be confusing. **WD Gold** is technically an enterprise drive (like Seagate Exos), while **WD Red Pro** is optimized specifically for NAS environments with better vibration compensation (NASware 3.0).
In our live tracking, WD Gold drives often appear slightly cheaper on Amazon UK, while Red Pro holds its value better on the used market due to the specialist NAS brand recognition.
Power Consumption Matters
With UK energy prices remaining a concern, the "Watts per TB" metric is worth considering. Helium-sealed drives (usually 12TB and above) run significantly cooler and use about 20-30% less power than older air-filled 8TB drives. Over a 5-year lifespan in a 4-bay NAS, this can save you £40-60 in electricity costs per drive.
Where to Buy in the UK?
Beyond Amazon and eBay, consider specialist UK retailers like **Scan**, **Overclockers UK**, and **Box**. They often have better shipping protection for OEM drives (non-retail boxes) which can be fragile if packed poorly.