is ok to pay 400.00 for checking the engine head gaskets and all cylinders? on 2000 Oldsmobile Alero

I was told the engine needs to be replaced there is oil all over around and I was offered a 85,000 engine for 600.00 aproximately

2 answers
pretty good price for an engine but if it runs ok I would check for an oil leak first before spending all that money
good price, does that incl labor?