What is the point of a book of values if no one in the area agrees? Isn't something worth exactly what someone will pay for it, no more, no less?
When valuing a gun, I look at what it is selling for online as a floor, and what it is selling for locally as a ceiling, and go from there. If used, I look at online auction sites to get an idea. If I am paying close to what it sells for online, or getting more than it goes for online, I consider that a win.
Of course if you have really old guns you want to value then ignore everything I'm saying and use the book.
i pretty much agree with what scotchman says as auctions reflect current values best. you have to average those out as well due to the ole 2 guys with deep pockets going for it. it's kinda funny, i have seen popular guns that brought good money fall out of favor in a years time or visa versa. an example of this is the browning high power which sat around the $ 500 mark for years them boom they shot up to $ 800-900 range. i expect they will drop down some in time. the very high end collectable and rare guns will always be steady as people with money are always seeking these. i think the other 95% of guns move with the economy and fads, popularity or laws. i think blue book & the standard book are two good reference books but i use them mostly for a rough starting point dollar wise and mostly about the information on a gun they provide.
Gun Broker always seems high. I usually check prices for new guns at Bud's, Hoffman's and a couple of well known others to base by decision but I did not know if that would be correct. Auctions seem to be inaccurate or at least to me they do.