Not an eBay watch, but from a dealer I've bought from in the past. His prices are, well, dealer's prices, but not outrageous, and his watchmaker knows what he's doing at least, so all watches are serviced well.
He has a gold-capped 2852 cal. 501, minimally polished Constellation with beautiful original domed dial for $1550, a pretty fair price for one in this condition, I think, and serviced:
http://www.watchestobuy.com/OmegaConstellation1954.htmClick to expand...