Used U.2 drives are the cheapest fast storage right now, and an adapter gets them running

Storage used to be the part of a build that was simple: you'd pick your type and capacity, look for something that was discounted, and then move on with more important decisions. In 2026, it can be one of the items that makes you want to forget about putting together a PC. AI demand has captured much of the NAND flash that's available, and consumers are left paying incredibly inflated prices. A 4TB SSD that could once be found for $300 or $400 is now close to $1,000.