What video program should i use?

so i have a macbook and am borad of imovie cuz their are not other effects i can use i already know all the tricks of the program and i need something new and i was looking at new ones on apple.com and their so frigging expinsve and my mom has a widow and i was useing wmm and its **** cuz i cant put music or put my videos on it and than i tried sony vegas and i coulded work with that one ethier and am just 12 and i cant offord one thats expensive and am looking at this one http://store.apple.com/us/product/MB642?mco=MTM4MTUwMjE but its too expiensive is their another program i can use that its not alot of money?