There USED to be alot of ps1 games worth getting. However, alot of them have been A) remade B) ported onto other systems
There are only a handful of games on ps1 i bet people are willing to play, and most of them are probably square titles, aka FF7. But square probably wants no part in a $6 pricing of their game, which they reap probably $4 from. They know if they remake ff7, or hell just re-release the damn thing they'll make more.
Most series on the ps1 haven't aged well in terms of graphics either, i mean the 64 is tolerable, but damn does the original RE look pixelated as all hell. Expect the only game worth downloading to never be downloaded, and thats symphony of the night. And yeah, i forgot, these games take up some massive space that will just eat into those gig packs for the psp, expect people to catch on quick to how much SUCK this whole ps3 psp transfer / psp memory stick is.
EDIT: when is say the graphics suck, i mean strickly for the psONE, i love all 2-D games so naturally i think the snes has better graphics then the psone. The only thing going for psone was the FMV, other wise all their games LOOKED like pixelated trash