Burned media (e.g. GD-Rs) prototypes tend to show up on eBay from time to time, but there's a lot of private selling going on too in forums like https://www.obs

Burned media (e.g. GD-Rs) prototypes tend to show up on eBay from time to time, but there's a lot of private selling going on too in forums like https://www.obscuregamers.com/builddb/ https://www.obscuregamers.com/builddb/ With Dreamcast and Xbox you can also find builds on the internal HDD of the development kits from the last time they were used. That's one of the things that makes Katanas/XDKs sell for so much.