For ebay I allways look for VERY sharp clear pics, more is better. and a good feedback score.
on a plane I would want a very precise description as well. if its pics of a box without inside pics you may end up with a box o crap. I bought a "kit" once on Eba^ and got a box of balsawood sheets etc but no plane parts. I did not pay to much so I didn't mind, but it was a good lesson.