you can't force everyone to be fair or even realistic when setting up their pricing though. some people spend a ton of time scanning, grading and posting books that are WAG graded or priced...and these threads drop like stones.
if people post FS: EVERYTHING AND YOUR MOTHER threads, then maybe they should be allowed to stay as long as they put up pics, descriptions and prices.
look at it this way; if you let people without scruples try and sell stuff, it just makes those who are scruple-filled look that much better