I like the idea, Generally speaking I think graal should have such a feature anyway so you can obtain items you like but can never get anymore. For instance I literally have about maybe 2-3 pages of hats full of stuff I will never use again for as long as I live, And since I got a 2p mount I never use regular mounts again even though I got like 10ish. So if I could hand it over to a player that needs it I'd have no problem with it at all. Plus I think this would be a great concept in making gralats and can open up more kinds of ideas and so on.
Graal Zone and Era ( I think Era) have a trading system and players somewhat learn the overall price of what each item Is worth. So to me, No reason classic couldn't do the same.