I traded a gun toward an LCP when the US gun-buying was at its peak (between around 2008 - 2009).
The gun I traded in - I had at least $750 into. The new LCP (with a free box of bullets) plus tax was nearly $500. I was told that that had to be the price as it cost the gun store owner a lot to get that gun, basically, I could take it or leave it -- it also happened to be the last new gun in the entire store!
I traded even and lost my shirt -- the only saving grace of all this is that I use the LCP daily whereas the gun I traded in might have been shot once or twice a year by me (I got it used).
Back in the late 80's or so, I bought a 99% used HK93 with OEM stock and also paratrooper forend and collapsible rear stock. Three 20 round magazines. I think I paid $700 for that gun, which was just like new. I had it for a while, but then I think I traded it toward something else, again, losing my shirt. Every time I have traded or sold any guns, I have always taken a beating. A few years ago, I decided, I don't have a large collection, I do have various guns that kind of cover anything I would ever need to use them for, so I am no longer selling, trading or getting rid of any guns, and I don't plan to buy any more guns as I am very satisfied with what I have.
I know it is all too easy to look at something long enough that I feel like I have to have it, even though it is something I may hardly ever use! I hope, as I get older, that I feel that way a lot less than I did when I was young and dumb.