This was awesome! I would've made the scoring of items speed up based on how many items were purchased, perhaps by saying items will take 1 second to score, but if there are more than 10 items, each item will take 10 seconds divided by the number of items, so it still takes 10 seconds, but if you get a ton of items, it scores them all really fast. I also noticed that if I double clicked on an item I could buy more than one of them, resulting in me buying multiple pianos for the price of one... But it was awesome!
And you're 14?! Keep making games like this and I bet you'll have a game paid game on steam sooner than you'd think.