Nice idea. This reminds me of one of the more successful and well liked
additions in Asheron's Call, the distributed quest system. Essentially certain
monsters would have something less than a 1% chance of dropping a component
that could be collected and used towards some of the nicer items in the game,
assuming you could find the PC or NPC with the skills to combine the
components. It was a hugely popular system, (in fact it almost entirely
replaced the existing coin economy) and one of the few fond memories I have of
that mismanaged and endlessly unbalanced game.
As an example, all golems had a chance of dropping a 'pyreal mote', which
could be combined into larger hunks. A skilled alchemist could combine the
larger hunks into a pyreal ingot, which could then be taken to a large
volcano, stamped with an enchanted glyph, and finally forged into a permanent
weapon only useable by the player who made it. The better your skill at using
the weapon, and the more skilled the alchemist who made the ingot, the better
a weapon you would get. These could later be boosted by finding enchanted
stones in some of the nastier dungeons.