Need repair advice
 

Hi - I'm about to buy an 08 Mini from a private owner but had it checked out and ran across 2 problems. The Mini service center said it needs a new vacuum pump and valve cover gasket. The seller took it to his mechanic who said that only the valve cover gasket needs replacing at a cost of $240. He said the vacuum pump is fine and the dealer just recommended it be replaced because of the leaking oil. I don't know who to believe. Any advice on what I should do before I make the purchase?