Sales for Rune pages IP sales????

So the other day i was thinking about a stupid Idea, why don't I ask riot and league community. So you know many ppl don't afford that much Rp to buy all rune pages or even 2 so why don't riot make a sale for it?? Then i was thinking about IP sales on any champions, so Riot can do this: They make 1 or 2 champions 50% off for buying with IP.