Getting down to the nitty gritty of the PSX demo collecting...anyoen ever see any of these in person? These are *known* to exist:
Besides these, the following need confirmation, as they are all unknown:
Crash Bash (Individual Demo in single sleeve)
Eidos Demo 2
Gran Turismo 2 (Individual Demo in single sleeve)
Rogue Trip (Retail, not Trade Demo)
Spyro: Year of Dragon (confirmed, looking for a Toys R Us Test Drive Sleeve)
This is more research than buying / selling, but if they exist, I need them, so if you have them / spot them, I am buying. : )