Damn it’s not that there are so few to buy from, it’s because everybody has learned NOT to go to Cabelas or Scheels to sell as they hose you. 40 cents on the dollar typical 50 if you are damn lucky. I see 2-3 auctions advertised each week in a (free, mailed) paper out of Albion that have guns consigned. In fact I posted a link to an auction of I think 86 old Winchester’s, Colts and Sharps plus other memorabilia that I specifically advised them against going to those 2. Quit blaming it on population and place the blame where it belongs.
If you're selling/trading to ANY retailer, they're "buying/trading" your rifle at wholesale so that they can sell it retail. Scheels bases what they're going to pay you off of a percentage of "Blue Book" value.
Let's say you buy a brand new SS Tikka T3 in 300Win for $600. After having your fillings knocked loose you decide that a .308 is a better choice. You have a used gun, they have to sell it as a used gun. They have to price that used gun at enough of a discount to a new one to entice someone to buy used instead of new. Let's say that your used Tikka is now worth ~$450. They can't give you $450, otherwise they're turning $$ without any profit. They're going to give you ~75% of what they feel the retail value of the used gun is. In the case of a Tikka that brand new was $600, You're now going to get $325-$350 on trade. They, like everyone else, do not work for free.
IME, the people who feel like retailers are "screwing them" on trade-ins or outright purchasing their firearms are folks who either:
A. Have dabbled in the gun-show market as either private sellers or maybe even had an FFL. The probably did so when saving $50 by buying used was enough, but, it's not anymore. Really what this person doesn't like is that they used to be on the other side of the table, buying @ wholesale and selling at retail.
B. People who buy things they can't afford in the 1st place and get pissed off when they find out that (pick your retailer) isn't a free gun-rental service for you to use for (pick your season) and then return.
One of the "B" examples that sticks in my head was a guy in his mid-late 20's who bought a Rem SP-10 Semi-Auto 10ga in late Sept and wanted to "return" it in early Dec for a full refund. His stated reason: "The flyway has moved way to the West and the Snow-Geese just don't come through here anymore". The shotgun has an obvious avid users season's worth of wear. He wanted/needed cash, when I told him what I'd pay him, he said, "No, I want to return it for full price". When I said no, he even had his mom come in and try to strike a better deal. Nothing doing.
Option B, happens DAILY in large volume retailers, take your pick on the sport. Ex.:
"Look at these great fish pictures, by the way, I'm going to have to return these waders and fly fishing gear, it's just not for me."
I'm done bird hunting, I want to return this shotgun but I'll use the $$ and buy a new rifle, deer season is coming. (Deer season ends), Yeah, I want to return this rifle it's not as accurate as I was hoping or it recoils too much, or this brake is too loud, or it's going to take me too long to draw another tag, etc, etc, etc............
Baseball season ends: My kid outgrew this glove, I want to return it for full price.
School starts in the fall: I want to return these golf clubs, I only used them twice and I don't really enjoy golfing (clubs look like they were used twice/wk.)
It goes on and on and never ends. Returned hunting boots in Jan. Return hockey gear in Apr. etc, etc, etc.
Somehow an awful lot of people have gotten the idea that retailers aren't there to sell them stuff. Retailers are their own personal little (or big) no-charge rental facility.