Joan of Arc is pretty much that price where I look (most recently Blockbuster), though the Sony store rarely drop the prices for their gaming stuff, so I guess that's a good thing.
I should hit up mine just because I haven't been there in a while.
YMMV but not too long ago I saw Rogue Galaxy for either $24.99 or $29.99 at the Sony Store. I'm pretty sure that the game is at least $49.99 at other places like Best Buy/EB Games, unless there has been a recent price drop that I'm not aware of.
Rogue Galaxy is most likely going Greatest Hits, I know Zellers has it for like $25-$30 as well, and I think I saw it somewhere else. Buy it now if you want original packaging?
Already picked up Rogue Galaxy for 29.99 at BlockBuster, so I wouldn't be suprised if it became a greatest hit. I also picked up GrimGrimoire for 29.99 at BlockBuster (of course, YMMV)