I already spent $10 to get the PS1 version of FF5 on PSN. I wish I had only spent $5 on that. Aren't most PSOne Classics about $6. I don't know why S-E felt that version, load times and all, was worth a premium price.
But I should probably shut up for proving them right.
Even though I already own a real copy of FF Anthology.
Only Final Fantasy and the Chrono series are overpriced. I bought front mission 3 for $5.99, even Legend of Dragoon is $6. For some reason the FF series are all $10. Even Chrono Trigger split from FFIV. and FF1 and 2 from Dawn of Souls are both $10.
The other overpriced games are GTA San Andreas of the PS2 classics which is $15 when almost all other PS2 games are $10 (except a few budget ones which are $6-7)
Edit: They had an Atlus sale in November I think it was, Catherine, P3 (PS2) and P3 (PSP) as well as Persona (PSP) and P2 IS (PSP) were all half price. I really should have picked up Catherine when it was $20.
PS1 games do not stretch to fit the screen, on HD tv's they have black borders (exactly the same as playing the games off a disk), unless you change your TV settings, but they do look fantastic (at least FM3 and BOF4 do). PS2 Classics do stretch to fit the screen, but they're not true HD. They still are supposed to look really, I intend to pick up P3 FES, if I do I'll find out whether they really do look better.
Edit 2: For Granz, there's no changes to the PS1 games, as for the PS2 games, they're all the same except they stretch to fit the screen, and if they had online game modes, then they've been removed. The only games that get added functionality are games labeled X:HD Edition. Those are listed under the PS3 games section of the store. Off the top of my head there's: Okami HD, MGS HD collection, Devil May Cry HD Collection, Sly Cooper HD Collection, Splinter Cell HD Collection, God of War HD Collection, and RE4. Those add trophy support, although if you're a stickler for trophies, I'd check online to see if they have full support. As RE4 HD only has a few trophies, whereas the other all have a full set.