Well, this is kinda like the token system for Bis, Rav EX and Alexander though with dungeon loot and only a specific item that you need to purchase. It's probably something that could be implemented, though I'm not too sure if it's something they would implement since, honestly, they want you to run it over and over and over and... You get the idea. I think it's personally feasible, but doubtful that we'd see something like this without a purely massive amount of interest.