Thats a lot of extra work for a potential buyer and leaves the door open to get burned.
Its not on the buyers shoulders to make sure the car is up to par. Of course if one wants an inspection on top of a safety its something you can arrange between yourself or they can do it on their own once they buy it.
The guidelines for a safety are pretty silly and open. Its almost up to the eye of the beholder so to speak.
so your mechanic says its cool...(but they dont do safety certs there). you buy it. take it to some place for safety and they ding you for a few things. not so fun.
Ive been to have cars safety'd before and the donkey put things down like new calipers needed when they were brand new. lol
so better save then sorry. have the seller deal with getting their car ready to sell and go from there.
if im buying something thats 5k or more(that i want to drive soon) i wont bother with as is cars.