Resale values can be found at online buying services like Edmunds or in used-car pricing guides like Kelley Blue Book (www.kbb.com).
The dealer invoice price is available at a number of websites and in printed pricing guides.
Each pricing guide receives data from different sources and makes different judgments about that data.
The magazine created a pricing guide for vintage jeans and included a teaser about a pair of buckle-backs that Farley had sold for $25,000 to a Japanese buyer.
He would later try to get a listing in a comic pricing guide, but the publishers said the character was "too obscure".
And a growing number of car buyers are checking pricing guides for information to determine how much a dealer paid for a car, limiting the dealer's ability to charge a large markup.
The New York company was one of the leading traders for serious collectors in the United States, with a catalogue that served as a pricing guide for American stamps.
In the United States, the price of a used car is tracked by a popular pricing guide called the 'blue book'.
The company uses a dynamic pricing guide based on current inventory ratios as well as the average closing prices for the products it has handled during the past month or so.
The agency makes it clear that checking a used-car pricing guide is only the first step.