Renting In Hextech Crafting Idea

I was just reading some other posts on the forum about how they are sad because they rented a champion shard or skin shard and it disappeared. They were complaining that Riot should put a warning so people know they won't get the shard back. I was thinking about it and I had a great idea:

If you rent a shard then you still get to keep the shard, but it also cost 20% of the original cost in essence to rent it. When you rent it the cost to unlock it permanently would also decrease by 20%. So you can rent it multiple times and it still costs the same each time. After you rent the shard 5 times, the cost would become zero and you would permanently unlock that skin or champion. If after you rented it you decided you don't like it and want to disenchant it, it would also give you 20% less essence back.

Example: I have a Braum shard in my loot and it cost 675 essence to permanently unlock it and gives you 325 essence when you disenchant it. So if I wanted to rent it, I would pay 135 blue essence, which is 80% of 675. Then I would get him for a week, but afterwards the shard would still be there. If I liked him I could pay 540 to unlock him permanently, because the price of that would go down 20%, I could disenchant him and take 260 blue essence because that is 80% of 325, or I could rent him for another 135 blue essence.