Any place where I can buy CHEAP and SMALL party lights?

Hey my friends and I wanted to have a small friendly party, and we were looking for small cheap lights (that work) like a small disco ball with colors and stuff. Nothing to expensive! I live in the bay area in California and I would prefer to buy the lights at a store and not have to buy online. Any suggestions of places I could visit? And see our price range is like about 50 dollars. Thanks. :) And remember! Nothing extravagant! We don't want to be DJ's just want to play some music with some nice colorful lights. Thanks. Haha