The company hasn't provided pricing or a release date, but we'd expect the Storage Expansion Card to be expensive when it ships. PCIe SSDs in this class are expensive as a general rule (Samsung's 1TB 970 Evo Plus is on sale for $200 on Amazon as we write this), and making one available in an easily removable format won't help keep the price down.

As with Microsoft, Seagate is keen to stress that you can't get away with a USB drive for Series X-optimized games. Conventional external drives just aren't fast enough -- they'll be fine for unoptimized Xbox One games as well as your Xbox 360 and original Xbox collections, but you'll be running into technical limits beyond that. Like it or not, this generation will likely be defined by pricey semi-proprietary drives, not to mention eventual revised console models with more built-in storage.