The WORST by far in my opinion (mine and mine alone) are pawnshops. I don't even really consider them legit sources for firearms. Every single one in my area are RIDICULOUS when it comes to prices. The vast majority of firearms they sell are complete junk. They are hocked for a quick buck by desperate folks. .
Pawnshops in your area must be a lot different than mine. Most of my firearms business is shotguns due to the fact that waterfowl and bird hunting is big here. In the past year or so I have had NIB A-5 Brownings, BPSs, and Citoris and NIB Remington Wingmasters and 1100s. Mostly from the 70's and 80's. And always have very good 870's and various Benellis, Winchesters and Mossbergs.
Yes, I do take in some junkers but I have a couple of customers that will buy most anything for $50 because they like to tinker with them.
And like my customers that do AR builds, They order themselves and I only charge $20 for the transfer fee. Everybody is happy.
To each his own, my 2 cents.......