Do like stated above. Clean your entire engine and rediagnose where the oil is really leaking from. Distributor o rings can leak and make it look like a couple other things. Cam seals leaking can drip down and look like your oil pan is leaking when it may actualy not be...
650 doesnt seem too outrageous to me for a shop to charge. The rear main seal requires trans. removal which is a couple hours itself. The cam seals require timing belt removal which while your in there might as well change it also...