I like the idea, and I'll go one further - items that can only be used by one player.
I hate crafter alts. So I suggest when you make a piece of super high-tech, it's only usable by the man who made it.
This handmade armour was made by Yellow Pete, and only fits a man of his exact measurements.
This hand crafted Plasma Rifle is so complicated only Greasy Joe can operate it.
Yes, it's a very fantasy RPG mechanic. But there's a reason so many MMOs have it. It works. It stops people churning out the best equipment and giving it out to everyone.