More Refunds for either RP or IP?

When I first got into league I ended up using all of my refunds rather quickly and have none left to use, what I'm wondering is if there would be a way to institute something in the store where you would be able to purchase more refunds for the right price (something like 500 RP or 4800 IP). If so, even if this would only be available using RP it would still generate some addition revenue which is never a bad thing.