I think the idea of running a pawn shop is a very good use of the theme! I think the design and animations of the customers are kinda cute and I like the variety of items they bring you! that's quite impressive given the time limit! I also think it was a nice touch for the buttons to resemble money. Music is very sweet and has chill vibe to it too!
I think it would be nice if there were like deadlines for amounts of money you had to earn to give the game some win / lose conditions. Also this isn't really a critique, but just some general advice, if you want the player to only be able to type numbers and not letters, you can use a spinbox node instead of line edit node.
Good Effort! : )