A close friend of mine bought a gun about a month ago.  With it he bought a box of "defensive" ammo.  He has never shot this gun and bought it after he shot the display model a few times.  Two days ago he asked me what I thought the gun was worth.  I asked why and was told that he is going to sell it.  I was shaking my head as I asked him why he is selling it.  His answer, "I need the money."
Ummm... you just bought the gun a month ago and no special circumstances have come up.  You didn't foresee your standard bills coming to get you just a month later?  Anywho... he bought the gun for about $525 bucks, out the door and when I told him he would be able to get $350 to $400 by selling to an individual.  He complained, stating it was brand new..never been fired.  I replied back, "It's like a car, once it's off the lot you lose money."  He was hoping to sell the gun back to the store, but I told him he would be lucky to make $300 bucks from the store.
The moral of this story, make sure you can afford your gun before you buy your gun.  Otherwise, you are just plain throwing away money.