Gashapon machines would work like barter stands except you'd get a random item from them. The merchant would charge a certain price (say, 1 gold coin) and the buyer would get a random item stored inside the machine (could be gems, fish, garbage, coins, Naruto fanfics written on parchment or whatever else the merchant chooses).
Not period appropriate, I know. But who cares? Chinese Lucky Cats aren't period appropriate either but they're in the game.
