No idea how much it is worth exactly.
True and sure thing that this is part of the Manic Miner Event MindArk is running right now. Later when all lost Items have been found there will be a ceremony to hand them over to an official MindArk Avatar, maybe Marco himself in person ;-)
There will be special Item Prices for every thing of those wich have been found.
Mega Gratz ! you are really lucky one ^^
Trying myself too to find one part while mining or drilling but like people said, the chance is really really low to get your hands on one of this Things.
For more Info you should visit the Entropia News Section on entropiauniverse.com
Fleur.