You can get bigger wallets in the game for 1000 and 5000 rupees. I think you get them from fairies. Trade stuff with the Gorons for Zunari and then buy that stuff for the joy pedastals to liquidate your funds. There are a lot of rupees in this game so don't be afraid to spend them. You can get charts and hearts buy paying to play minigames. There is also a nightly auction on Windfall Island.