Prebuy oversight:    Close supervision of the prepurchase inspection and condition evaluation is necessary when buying an aircraft.  A good prebuy inspection will identify hundreds of items in categories such as: inop, worn, un-airworthy, unusual wear, % remaining life, needs further investigation, etc.  All of these categories (except un-airworthy) can be negotiated.  Each company should be represented by an experienced aircraft maintenance professional to advocate for their position.  With parts such as brake units and windshields costing upward to 50k plus installation you wouldn't want to be on the wrong side of a bad call.