One would actually have to hear a used LP to rate it accurately. I think most sellers rate LP's based on visual inspection. My experience is that visual is a good indicator but no guarantee of quality. I have bought LP's that looked good and sounded poor and LP's that look suspect but sounded good. Having said all that I much prefer examining them myself before buying. I have had pretty good luck with used LP's bought locally and on audiogon. Never bought LP's on Audiogon.
