Simple solution for Un-tradables. Rather than having them disappear forever, require the player to 'charge' them with GP before entering the wilderness. When the player dies, this charge is dropped as GP, giving a reward to the killer while giving risk to the wearer. For example: Fire Cape charged for 30,000 GP Player dies Fire Cape is left in Inventory, but loses it's charge. 30k is left on the ground for the Pker.
This is quite a simple solution to a problem that shouldn't be a problem in the first place.