I once tried to do a trade on an Smith & Wesson AR-15 with many upgrades and some fat ("heavy-set" is the nicer description) and gray long bearded employee wouldn't even trade a $500 Glock OUTRIGHT. He then told me that he could not even give me $400 for it since the AR craze is "now over." This was around the very beginning of March 2013. So I walked out annoyed with their pathetic offer. When I walked out of the store I ran into one of my Dad's old friends and I started talking to him and showing him the AR that I tried to sell in the store. This same gray bearded employee ran out through the doors and said to the man I was talking to, "IS HE TRYING TO SELL THIS GUN TO YOU!?" Then his screaming was directed at me, "GUN SALES ON OUR PROPERTY IS NOT TOLERATED. GET THE HELL OUT OF HERE BEFORE I HAVE TO KICK YOUR ASS OUT!" I was like, WOW, I was talking to someone I know...but Okay bud. Also...this wasn't my only bad dealing with this employee...but this was the worst. The other times were before this happened and just him speaking to me like I was dirt on the bottom of a shoe and like I didn't know a thing about guns.
SO, I took that EXACT SAME S&W AR-15 into Plainfield Shooting Supplies recently (very end of May 2013...obviously after all the AR craziness) and spoke directly with Bob. I traded it for a $595 Glock, $150 cash, 2 - 50 Round boxes of regular ball 9mm ammo, and also a 25 round box of 9mm hollowpoints. That AR sat on their shelf for less than 2 hours...sold that same day. Clearly there was still enough room for profit, while still being priced low enough that someone would buy it so quickly.
I just won't go back into Fort Liberty....which is fine...I'm not saddened by this at all. Especially when there are several other much better shops to go to. (Plainfield Shooting Supplies, Indy Trading Post, Premier Arms)
I have no doubt found that Bob at PSS will give the best trade in price of the shops around. You can certainly get more on the private sale, but dealing with Bob is quick and easy, and my experiences have always been that he makes very fair offers that still leave him some meat on the bone. He does a ton of business and on a popular item that he knows he can turn will make a good offer, and he is smart enough to know that making some on both ends of the transaction (some on the new gun he is including in the trade, and some on the used gun he is taking in) it is better than trying to make a killing on the used gun.
That said, I don't get upset if a shop doesn't make me a good offer, that part is just business. I've had several shops not even come close to what Bob has offered me on a trade.
However, the part about the Fort Liberty person running out to yell at you would have royally irked me too, and would kill any future business I would do with them, if it happened to me.