FTP Sales?

Hey guys, I just had a great idea! How about whoever is on the FTP (Free To Play) List gets let's say a 20-30% off on RP (This will—hopefully—not affect the weekly sales of champions)? I'd say this is one of the best ideas I've ever had. It helps Riot earn some extra money because if a summoner sees a champion he/she is good with, then they can buy it with RP with a slight price reduction. Since you can play the champions for free anyway, why not let them buy it right then and there? They wouldn't have to wait a week or longer for a great sale on a champion!