The Blue Book of Gun Values is an excellent reference and I use it a lot as a guide on pricing. Sometimes I'm looking at some gun I know absolutely nothing about and I start at the Blue Book to give me a rough value. I also assume I will be selling generlly at a price less than the Blue Book IF I sell to a dealer. I try not to sell to dealers, but like cars, I often do anyway. I know how it works and accept it.
If you don't have a Blue Book, the new one for 2008 will be coming out in the next month. I recommend that you buy a copy for the information and use it as a guide. There is none better available.
The most current place to find an approximate value these days is to look at closed auction prices on GunBroker or Auciton Arms if you want to go to the effort. Make sure you are comparing apples and apples. Forums are okay, but you get a wide range of "values" as people will be telling you what they paid two years ago like it is the current price. You need to know the market if you are trying to make money at it.
I pretty much only pay attention to Colts and Smith handguns as far as prcing goes. Most everything else, I can only guess at a value. That is where the Blue Book comes it as well as my instincts from attending many gunshows.
Pricing in the Blue Book is probably 3-6 months out of date at the time of publication and I doubt they check the market on every single gun that is listed. They may apply some sort of "inflation" factor to pricing on some guns from year to year. That still does not change the fact that pricing on firearms is a supply and demand thing. Some things go up a lot and some things just stay about the same. New gun prices exercise a huge control on the used gun market. The collector market is a different animal and it can be quite fluid from month to month.
The value of a gun is what you can sell it for. A $1,000 gun to one person is a $600 gun to another.
