OP, there is no "price" for a used gun - it is what you and a buyer agree to. Post #2 got a lot of it - you need to put in some hours of real research, not chatting with neighbourhood talkers - auctions, etc. - to know what similar may have sold for - and do not overlook the extra fees that any auction buyer had to pay on top of the bid price. You still have to find that buyer or at least a similar buyer, if you want to get that total price, which also includes deducting what the auction consigner would have received after paying the various selling fees.
And, on a different level, you are the one who has to live with you after the sale. How much are you going to be happy selling it for? If you paid $750 new 10 years ago, and think you will get $800 today, then post it that way - will find out if there is a buyer out there who agrees, or not. May as well figure out before hand whether that includes shipping or not, and how are you going to do that? That is the only way to find out, I think. If you posted it for $650 and it goes in 10 minutes, you are always left wondering if you could have got more for it - and how much does that really matter to you?? Only you can answer. Gone, for sure, with $650 in your bank, or still there because you want $150 more. Like Post #2 says, try and disconnect the emotional attachment to it.
So maybe think like - it is not worth what you paid for it, it is "worth" what someone else will pay for it, to you, today. That might be more or might be less than you bought it for, but what you paid, is, or should be, sort of irrelevant about what someone else will pay today...
