Solution to make items free after purchasing?

Does anyone have a solution for making items 1-time purchase in a shop? In my pinball game I have skins that cost points and id like them to be 1 time purchasable and after that I want them to be free. Do I need to have a player variable hasPurchasedSkin1? and then the item twice in the shop, one with req hasPurchasedSkin1 as false with cost X points and one hasPurchPurchasedSkin1 true as free? That seems super tedious but I can’t think of another solution.

You can set “requirements” in shops, so, if player purchases an item, you can set player’s attribute X as 1 (default value is 2), and make it, so certain items in a shop requires X as 2.