During the game you will meet a man who wants to set up his own shop. Depending on how much you give him, the shop will have different wares:

1-100: Basic weapons.
101-500: Basic skills
501-1000: Better weapons and some skills.
1001-2000: Better skills, but more items then skills.
2001-2500: Mega heal kits and such at low prices.
2501-3000: Your choice of good weapons, items, skills, armor and a mini-game.
3001-5000: Great weapons for Lin, poor weapons for Ryu and Nina, and good spells for Nina.
5001-10000: Your choice of great weapons, skills, spells, stat increasers, armor, items, but no mini-game.