Sell champions every third month

What if you could sell 3 champs every third month, and buy 1 sell for 100 rp. (lets call it sell) If we say this, you have 0/3 , umm idk what to call it... sell champion, and then you wan't to sell your champion but don't have any left, you'd be able to buy one for 100 rp. I know this allready exist with that you can sell 3 champs but thats just 3 times and then you can't sell anymore. And you would just be able to buy 3/3 and not more.

Post below if you got more ideas and what you think about it [slayer-pantheon-thumbs] Thanks ;)