The new M4-based Mac Mini starts at 256GB of storage. If all you want is more space, you can get a 512GB module for $200, a 1TB for $400, or a 2TB for $800. If you've got access to the right tools, that upgrade can be almost free—a 1TB NAND flash ship can cost as little as $20-30.

However, as noted by MacRumors, it’s probably similar to their storage with only the NAND chips on board and the controller is still embedded in the SoC, tightly restricting any possible DIY upgrade or repair options.