That's quite a find. I would go the ebay route. Right now the ebay marked for games seems pretty depressed to me. If you want top value you might want to wait and see if the economy turns around a bit. I remember many a night with the old master pack (insert joke here).
Ebay is almost always a buyers market for games in the summer. Best prices are going to be from October through early January; the down economy may continue to depress things some, but now is a lousy time to ebay any high-value game item.