Yea, buying champions sounds dumb, but given how many champions there are, I doubt their algorithms for determining which champions pop up can ever be perfect for providing a balanced experience. Maybe a system where you can purchase champions, or prevent a champion from being purchased (bans). Champions you "order" can appear off to the side of the carousel for a random carousel round once, and if you pick that champion, you cannot choose from the carousel. This champion you ordered can come with a random item. As for the cost, double its default price?