Steps in comments

1. Get knife from dark world
2. Go to number world and go to the stabbing room
3. Kill everyone.
4. Go to puddle world, find a pink staircase, there should be a vending machine on the other side.
5. use your ten from the victims
6. Profit

*yen

Scratch that, instead of going to number world, go to the sheildfolk world, then go through the static maze, go to the fc house, figure out a way to get to the goblin room, bc the goblins have a 1/4 chance to drop yen instead of 1/8.