The WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4) costs $0.0342/GB while the Seagate Expansion Desktop 16TB External Hard Drive – USB 3.0, 3.5" HDD for Windows & Mac, Plug-and-Play Backup Storage - STKP16000400 costs $0.0329/GB. Seagate Expansion Desktop 16TB External Hard Drive – USB 3.0, 3.5" HDD for Windows & Mac, Plug-and-Play Backup Storage - STKP16000400 offers 4% better value per gigabyte as of August 2026. Both products are available on BuyPerUnit with prices from Amazon, Best Buy, and Newegg.
WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4) vs Seagate Expansion Desktop 16TB External Hard Drive – USB 3.0, 3.5" HDD for Windows & Mac, Plug-and-Play Backup Storage - STKP16000400 — Which Is Better Value?
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Specification Comparison
| Spec | WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4) | Seagate Expansion Desktop 16TB External Hard Drive – USB 3.0, 3.5" HDD for Windows & Mac, Plug-and-Play Backup Storage - STKP16000400 |
|---|---|---|
| Brand | Western Digital | Seagate |
| Capacity | 18TB | 16 TB |
| $/GB | $0.0342 | $0.0329 |
| Price | $615.95 | $526.04 |
| Retailer | Newegg | Amazon |
| Category | Hard Drives (HDD) | Hard Drives (HDD) |
| Subcategory | hdd | hdd |
Price Across Retailers
WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4)
Seagate Expansion Desktop 16TB External Hard Drive – USB 3.0, 3.5" HDD for Windows & Mac, Plug-and-Play Backup Storage - STKP16000400
Which Should You Buy?
Based on current pricing data, the Seagate Expansion Desktop 16TB External Hard Drive – USB 3.0, 3.5" HDD for Windows & Mac, Plug-and-Play Backup Storage - STKP16000400 offers better value at $0.0329//GB compared to the WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4) at $0.0342//GB — that's roughly 4% less per gigabyte.
The best deal for the Seagate Expansion Desktop 16TB External Hard Drive – USB 3.0, 3.5" HDD for Windows & Mac, Plug-and-Play Backup Storage - STKP16000400 is $526.04 at Amazon, while the WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4) starts at $615.95 at Newegg.
However, price per gigabyte isn't everything — consider factors like warranty, performance specs, brand reliability, and your specific capacity needs. Check each WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4) and Seagate Expansion Desktop 16TB External Hard Drive – USB 3.0, 3.5" HDD for Windows & Mac, Plug-and-Play Backup Storage - STKP16000400 product page for detailed specifications and price history.
Frequently Asked Questions
Is WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4) or Seagate Expansion Desktop 16TB External Hard Drive – USB 3.0, 3.5" HDD for Windows & Mac, Plug-and-Play Backup Storage - STKP16000400 a better deal?
As of August 2026, Seagate Expansion Desktop 16TB External Hard Drive – USB 3.0, 3.5" HDD for Windows & Mac, Plug-and-Play Backup Storage - STKP16000400 offers better value at $0.0329//GB compared to WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4) at $0.0342//GB. That is approximately 4% better value per gigabyte.
What is the price per GB of WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4)?
The WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4) is currently priced at $0.0342/GB ($615.95 for 18TB) at Newegg.
Where can I buy Seagate Expansion Desktop 16TB External Hard Drive – USB 3.0, 3.5" HDD for Windows & Mac, Plug-and-Play Backup Storage - STKP16000400 for the cheapest price?
The cheapest price for the Seagate Expansion Desktop 16TB External Hard Drive – USB 3.0, 3.5" HDD for Windows & Mac, Plug-and-Play Backup Storage - STKP16000400 is $526.04 at Amazon, which works out to $0.0329/GB.