"Undo last purchase" may come to LoL live servers
A redditor by the name of Impermeable caught a little icon showing that you can now resell items that you may have accidentally purchased so long as you've not left the fountain or have done a game -action. While this is not on the live servers yet and simply on the public beta realm, there's a very high chance on many of the things from PBE making it into the live servers.
Does this make it a little too noob-friendly or forgiving? Possibly, but for newer players or perhaps players with rare mouse issues, this could be a remedy to double-purchasing an item or purchasing the wrong item when going for a very specific build. Do note that "Undo" seems to be a completely seperate action from "Sell".