Depends on who is doing the buying and what the gun is. The bluebook is a reference price. When I sold my ruger sr556 I got a little more than blue book. Most gunshoos will offer 50% of bb value and will often down play its value
It varies greatly just depends on the shop. Same for consignment sales.
"Gun control: The theory that a woman found dead in an alley, raped and strangled with her panty hose, is somehow morally superior to a woman explaining to police how her attacker got that fatal bullet wound." — L. Neil Smith
The problem with being stupid is you cannot simply decide to stop doing dumb things...
"I crapped my pants to avoid the draft!!" -Ted Nugent