The WD Red Pro 18TB NAS Internal Hard Drive HDD - 7200 RPM, SATA 6Gb/s, CMR, 512MB Cache, 3.5' - WD181KFGX costs $0.0417/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 $0.0301/GB. Seagate Expansion Desktop 16TB External Hard Drive – USB 3.0, 3.5" HDD for Windows & Mac, Plug-and-Play Backup Storage - STKP16000400 offers 28% better value per gigabyte as of August 2026. Both products are available on BuyPerUnit with prices from Amazon, Best Buy, and Newegg.

WD Red Pro 18TB NAS Internal Hard Drive HDD - 7200 RPM, SATA 6Gb/s, CMR, 512MB Cache, 3.5' - WD181KFGX 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

SpecWD Red Pro 18TB NAS Internal Hard Drive HDD - 7200 RPM, SATA 6Gb/s, CMR, 512MB Cache, 3.5' - WD181KFGXSeagate Expansion Desktop 16TB External Hard Drive – USB 3.0, 3.5" HDD for Windows & Mac, Plug-and-Play Backup Storage - STKP16000400
BrandWestern DigitalSeagate
Capacity18TB16 TB
$/GB$0.0417$0.0301
Price$749.99$481.81
RetailerNeweggAmazon
CategoryHard Drives (HDD)Hard Drives (HDD)
Subcategoryhddhdd

Price Across Retailers

WD Red Pro 18TB NAS Internal Hard Drive HDD - 7200 RPM, SATA 6Gb/s, CMR, 512MB Cache, 3.5' - WD181KFGX

Newegg$0.0417//GB
$749.99Buy
Newegg$0.0442//GB
$794.99Buy
Newegg$0.0444//GB
$799.95Buy
Newegg$0.0500//GB
$900.40Buy
Newegg$0.0514//GB
$924.45Buy
Newegg$0.0520//GB
$935.83Buy

Seagate Expansion Desktop 16TB External Hard Drive – USB 3.0, 3.5" HDD for Windows & Mac, Plug-and-Play Backup Storage - STKP16000400

Amazon$0.0301//GB
$481.81Buy

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 $0.0301//GB compared to the WD Red Pro 18TB NAS Internal Hard Drive HDD - 7200 RPM, SATA 6Gb/s, CMR, 512MB Cache, 3.5' - WD181KFGX at $0.0417//GB — that's roughly 28% 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 $481.81 at Amazon, while the WD Red Pro 18TB NAS Internal Hard Drive HDD - 7200 RPM, SATA 6Gb/s, CMR, 512MB Cache, 3.5' - WD181KFGX starts at $749.99 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 Red Pro 18TB NAS Internal Hard Drive HDD - 7200 RPM, SATA 6Gb/s, CMR, 512MB Cache, 3.5' - WD181KFGX 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 Red Pro 18TB NAS Internal Hard Drive HDD - 7200 RPM, SATA 6Gb/s, CMR, 512MB Cache, 3.5' - WD181KFGX 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 $0.0301//GB compared to WD Red Pro 18TB NAS Internal Hard Drive HDD - 7200 RPM, SATA 6Gb/s, CMR, 512MB Cache, 3.5' - WD181KFGX at $0.0417//GB. That is approximately 28% better value per gigabyte.

What is the price per GB of WD Red Pro 18TB NAS Internal Hard Drive HDD - 7200 RPM, SATA 6Gb/s, CMR, 512MB Cache, 3.5' - WD181KFGX?

The WD Red Pro 18TB NAS Internal Hard Drive HDD - 7200 RPM, SATA 6Gb/s, CMR, 512MB Cache, 3.5' - WD181KFGX is currently priced at $0.0417/GB ($749.99 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 $481.81 at Amazon, which works out to $0.0301/GB.

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