rent skins investment goes towards purchasing it if you ever wish to
would be a bit like in aram you can rent a skin for 1 game. but the gold you spent on it would go towards you being able to purchase said skin if you ever chose to. except without the ip boost. could rent a skin for like the whole day or like 5 games. would have charges on how many times you can use it.
say it cost 90 rp for 5 charges. if you rent it 10 times youd unlock it if it cost 900 gold can gift charges too you can fill the difference essentially if you ever decide to purchase it. would be a good way to test skins out if your not quite sold as to whether or not to get it.