A few things to consider:
1) Blue book prices are heavily biased toward gun shops who by design buy low and sell high. They are also out of date the day they are printed and also do not reflect regional differences in prices for various firearms.
2) The same applies to the S&W book except it's revised far less often and is even more out of date.
3) Local gun shops on average will pay you only 50% of the expected market value of the firearm. Some will tell you they pay 60%, but they are usually lying or are starting from a lower expected retail sale figure.
That's because they have a fair amount of overhead paying rent, utilities, wages for staff and tie up a lot of money keeping items in inventory until they sell.
In rare cases, you might get more if the local gun shops knows someone who is interested in what you are offering and knows they can turn it back into money almost immediately. The *might* however means that they know they can turn it over quickly AND you've already rejected their 50% offer and are about to walk out the door.
Sometimes they might give you a bit more just because you are a really good customer and they don't want to offend you.
3) If you sell on consignment through a local gun shop, you'll probably get about 80% of the fair market value, as the shop will keep 20% for logging it in and out and keeping it on their shelves.
20% is fair because it's taking up shelf space and sales staff time, while at the same time they don't have money tied up while it sits on the shelf.
4) Many people will over value a firearm they want to sell, because they see it as an investment, want to make a profit, or just have an emotional attachment to it. Similarly, some firearms have a family history.
For example I looked at a Walther P1 once that was claimed to be a bring back from WWII by the seller's father and he even had a picture of his father in uniform with the alleged pistol as "proof". Well sure, his father may have actually brought back the P.38 pistol in the picture, but the fact remained that the pistol for sale was a post war manufactured P1. Maybe he sold the P.38 when times were tough and replaced it with a P1 later. Who knows.
I don't really care however as even if it was a P.38 the story is just a story unless it also had the bring back paperwork. My response to that kind of emotional family history pricing is to just remark that I would not feel right buying a family heirloom and walk away. If they chase me out the door and offer it as a reasonable P1 price, I might reconsider.
In contrast many potential buyers will tell you a firearm is over priced, or if you just bought it that you paid too much. Their metric is almost always one of the following:
- the price they paid a few to several years ago;
- they are people who really should have an FFL as they primarily buy guns with an eye toward selling them at a profit within the next year or so - in other words looking for under priced firearms they can make a quick buck on; or
- they got a screaming deal from a shop that could not unload a similar niche firearm.
4) On-line auctions have really changed the market for firearms.
In the past an unusual, less common or niche market firearm would sit on a shelf in a local gun shop for literally years until the right buyer came along who knew its value and was willing to pay that to take it home. More often it would sit there a year or so and then get sold at less than market value to someone who showed even a little interest in it and was willing to pay enough for it so that the shop owner wasn't going to lose money on it. In other words, the gun shop owner needed to turn it back into money that he could roll over into other firearms that he could sell quickly.
Some folks, me included would go looking for those kinds of deals. They are now few and far between as sites like GB and GA enable them to reach those niche buyers quickly. That means they don't have money tied up in a firearm for potentially years before they can get the full market value for it.
There are of course folks who decry GB and other on-line auction sites as inflating the value of firearms as they claim people get in bidding wars and inflate the prices. There are the rare instances where two or more buyers who obviously don't know the value of an item get out of control and way over bid, but those are the exceptions. And you can argue that even as exceptional examples, they still reflect the market value when stupid people bid on an item.
In most cases however, searching the recent completed auctions where a sale actually happened for a firearm of the same model, dash number configuration and condition will give you a half dozen or so examples that help you set a pretty accurate price on a national rather than regional level.
The unfair part of all this is that most local gun shops also list their less common firearms on GB or GA, so they move them pretty quickly. Yet they'll still only give you 50% of that market value when you bring one in to sell it.
One of the local shops here lists on GB frequently, and in fact I'll search GB by seller and see what they have listed recently rather than going into the shop, particularly with the current unpleasantness. Often the starting bid or even the buy it now price is lower than the price they have marked on the firearm in the store. Obviously, that's good information to have when starting your negotiation on the item.