-Look for planking on the playfield by the slings.
-Make sure the mist mech works.
-Check for wear on the rat hole.
-Make sure the ramps are are ok.
BSD is one of my personal favorite machines. I do own one and play it almost daily. The only thing I don’t like about the game is that it is very time consuming to shop. Good luck with the purchase. You could be buying one of the best.