Well a 2tb SSD is $350, so that's wasn't feasible. Sounds to me someone needs to clean up their drive or you need to buy HHD server to store some of your games.
A 2TB SSD with better raw speed than the XSX SSD is $235 on Amazon... 3500mb/s read, 3000mb/s write. XSX SSD is 2400mb/s
This is why I like sony solution better, just allowing normal SSDs, and useing normal ports.
Market competion will drive prices of these SSDs down over time, and it ll be cheap(er) to add in more storage to your console.
Sony tried the expensive storage solutions with the Vita, and after that, they were done with perpriatary solutions of such.