I'm looking for a new video editor?

Ok so right now i use WMM (windows movie maker) i like how it works fast but there are just not enough editing options, i use WMM to make youtube videos and family videos. I really want some new effects! I don't wanna pay more than $50 becuase im only 13 so its pretty much just for fun. I have a pc and i want to be able 2 buy the software in a store like bestbuy or raidioshack. I CANT BUY IT ONLINE please if you know of a good one plz tell me