I guess it would depend on if you were advertising for a single,twin,four,six or eight or ten or twelve cyl. wouldn't it,if you advertised a set for a V-8 and only sent four you would be a real jerk wouldn't you.
Have you ever ordered a custom set of pistons from Ross or Wiesco? You get a set of 10 for a V8. But this isn't the point, had he asked or asked for a picture, IE: communication, this wouldn't even a thread now would it!