IMO-I think what a seller has as his “ wall books” is indicative of what kind of sale is going to happen - guys that tend to have just all star killer stuff are usually overpriced , guys that have $20 books marked up as “ keys” are generally overpriced . I try to do business with guys that love comics - they collect , they buy , the sell to offshoot some expenses and normally have other jobs . Going to conventions for me is more about potentially getting a book signed , filling gaps in my runs and having excellent conversation than for scoring a FF#1 which is way outta my price range anyway .