I don't see the advantage in that. I generally say 'yes' to requests then hope I find the item. If not they are unlucky. They'll have forgotten all about the request the next morning, anyway.

There's no real gain to a player apart from getting random (generally useless) items in exchange. When my tool tray gets full I'll empty it by selling items to the store and there's little difference in selling the found items or selling their gifts.