Premise: An altar/machine in game left by a an ancient empire (Netheril, Imaskar, Illefarn, Aryvandaar, whatever) which can impart an enchantment to an item when a magical focus is provided.
Function: An item placed on the altar may receive the following bonus when altar is activated:
An item with one or less item property may receive either a +4 enchantment, +4 deflection or +4 armor bonus
An item with two or more item properties may receive a +3 bonus
An item with three or more properties may receive a +2 bonus
Limitations: May only be used once per calendar year per player. A use of the altar requires
Pros: Enchanting is egalitarian; the top few crafters can't monopolize enchanting and only do it for their friends
Cons: I can't think of any way this could be exploited or would result in power creep...can you guys?

EDIT: Ok I think I found a really obvious flaw in my own idea, everyone could make +4 mithral full plate
