Curse Store System

MC: "Man, I want that new game but I need money to buy it and my allowance doesn't come next month!" ???: "You want money, I know a way to make some." MC: "Oh, how so?" ???: "Want to be an entrepreneur? Then open your very own store!!" MC: "That sounds nice but I need money to open and run a shop along with other things." ???: "No no, you misunderstood my intentions. I'm giving you my old store to run on your own!!" MC: "What's the catch?" ???: "Haha, it seems you are smarter then I thought. You see the store itself is a little bit special and you have to sell special items." MC: "Special how?" ???: "It's a curse store and the items, of course, are cursed!!"