I've seen over the years various attempts to print "Blue Book" values for antique and collectable bikes, cars and motorcycles that cannot predict "market" or sale prices due to the variation in perceived condition, sale venue, bidding competition, etc. These forum postings can help establish the range of prices recently or historically realized, but it becomes very noticable that a lot of factors influence the sale prices beside condition and desirability. Some folks like to be as fair as they can to both themselves and the other party to establish a "fair price" and this is a good practice. Letting someone know when they might be offering an item for sale at an unusually low price to be fair is a good ethical practice and it can be tempting not to say anything. This also works the other way when selling an item for a unusually high price because the buyer is a novice. Wheeling and dealing can also be like a poker game and players don't like to show their hand. Asking for a fair price appraisal depends on many factors that can cause some pretty big discrepencies in the responses from members of a forum like this. A particular bike like the Phantom mentioned in the inquiry could bring a price range from maybe $1000 to $1600 on average (throwing out uncommonly high and low prices) but that is just my guess based on information that is second hand from the internet. Bikeman and Shawn and others have offered some good info based on their experience, but actual milage may vary.