everyone's right, after getting to the ice cave, money shouldn't be a problem. Now, about skills. You could do cancel trick, but some ppl consider this cheating(I'm up in the air about this, mostly because they didn't take it out for origins.) Other than that, just have ALOT of patience. For HP and MP, you could try the swap trick (do this later in the game) or have your characters use their spells on each other.

If you have decent HP (about 200 per character) go a little north of Fynn, and kill some Magicians (Wizards? Sorcerers? I forget what they're called.) They usually drop Berserk Spells, which sell for 5000 Gil a piece. They also sometimes drop a Mage Staff, ehich when used as an item, casts Bolt 5.