I have absolutly no idea why I am making a thread on this...
I've noticed that FF games seem to have items you can't sell, at all - obviously all Key Items can't be sold, but sometimes it's regular items or mostly weapons.
FFVII doesn't seam to like it when you try to sell standard weapons (the ones each chracter starts off with) I don't understand that at all - also why didn't FFIX do that? There's a fight in there that depends you using your standard weapons, but they're not needed in FFVII.
Another thing I've noticed is that "important" equipment can't be sold. By "important" I mean it means something to the character; again in FFVII there are the Silver Armlet, and the Seraph comb for example.
Any others?