Just a suggestion, but there are heroes who I have bought that I now hate. It doesn't even have to be full price. I know people are gonna say to just earn the money again, but this is just a suggestion.

Yes I agree, we may have no use for some champions anymore and want IP back for buying runes or a new champion.

I agree. Sometimes, I buy a champ that I thought I really wanted only to suck with them.

Maybe get 25-50% of the IP cost back when you sell a champ/rune?

I'm guessing the answer is no. If you need more IP or heroes, you're more likely to buy RP or the retail version of the game. Adding the ability to sell heroes wouldn't help Riot Games.

They've got to eat too.

Not possible because it's unfair for those who bought with RP.