Playing Omega (roguelike) on ATARI ST, there were food shops that you could buy stacks of fried lizard bites if I remember correctly? Anyways, I found out that if you bought the max amount 99999999, it would actually give you money. Baby's first buffer overflow. The only issue is that it would also put that amount in your inventory, so you were basically too slow to move and had to drop each stack so my towns were littered with stacks of lizard bites. I'm not sure where the bug was introduced and I never found it in the PC versions later on when I looked.