You'll need:
- any browser
- ce 5.5
- Go into Ninja Saga. (link above)
- Go to Shop.
- Select the item to sell. (do NOT sell it yet)
- Select browser as ce5.5 process and enable speedhack.
- Select '0' as speedhack value.
- Now in Ninja Saga, spam clicks on "Sell" as many times as you want.
- Change the value in ce5.5 back to '1'
- Now watch as you gain all the coins. This CAN BE SAVED! Just make sure to purchase some items to auto save the game.