If you're running out of space on your Xbox Series X or Series S, check out Amazon's deals on the WD Black C50 and Seagate Expansion Cards before Prime Big Deal Days ends tonight at 12 AM PT. The WD Black C50 1TB is discounted to $110 (was $150), but make sure to click the coupon on the store page to get the full discount. Seagate's 1TB model is bit more expensive at $123.49, while both 2TB models are on sale for $200.WD Black C50 Xbox Expansion Card1TB -- $110 ($150)2TB -- $200 ($250)Seagate Xbox Expansion Card1TB -- $123.49 ($160)2TB -- $200 ($250)If you're an Xbox Game Pass subscriber, you've probably noticed that your storage space can disappear fast. Speaking of Game Pass, with substantial price increases on the horizon--Game Ultimate will soon be $30/month--you may want to stock up on prepaid codes. Amazon is selling 3-month Game Pass Ultimate codes for $57 ($19/month). The C50 launched in 2023 to compete with Seagate's Expansion Card, the only other officially licensed storage expansion option for Xbox Series X|S. Seagate's Expansion Cards used to be incredibly expensive, but the arrival of the C50 led to price drops.Western Digital and Seagate Xbox Expansion Cards offer the same functionality. You simply insert the proprietary storage card into the expansion slot on the back of your console. Your Xbox will recognize the card and allow you to choose if you want to use internal storage or expansion storage as your primary install location. That's the whole installation process; these truly are plug-and-play storage solutions.Regular external hard drives can store Xbox Series X|S games, but you need to transfer them back to the console's internal drive to actually play them. Xbox Expansion Cards, on the other hand, can store and load games; these nifty accessories act as an extension of your SSD.