I hear it every day. Just had a customer come in to the store with a Ruger SR9 he wanted to sell that had obviously been used and carried and dropped on the ground at least once.
I offered him $225 for the gun. He snatched it out of my hands and told me he knew what they were worth and there was no way he would take so little. I asked him how much he wanted for it and he told me $350. I just had to chuckle a little when I told him that he would never get that at a gun shop considering what a dealer buys them for new. He stormed out of the store and didn't even give me the chance to explain my offer.
Some people you just can't help.
The same thing happens with Browning A5's. They aren't worth nearly what people think they are worth. You'd think they were made of gold or something.