I have a feeling that it's likely to be a stupid proposal (in a sense that I would be surprised if no one suggested it yet at this point, still nothing like that was implemented so there should be some reason) but logical wise I don't see any issue about it.
So, like the topic title suggests, could we have KP Coupons in Kafra Shop which could be traded and used to exchange them for KP back? Like, you buy KP100 coupon for 100 KP, give it to other player and he could exchange it for 100 KP.
Money-wise, it doesn't seem to be a problem - instead of one player, other player will spend money to purchase KP. True, a lot of things in Kafra Shop can be purchased by asking other players to buy in your stead but some items aren't tradeable (like Lucky/Groovy boxes where you would have to rely on other player's honesty that he won't deceive you with box's content).
Is it possible (if no - the reason)?