I'm seeing people offer guns for sale on "buy/trade" boards at excessive prices, and posting a "don't complain" edict along with their ad. Maybe I'm just old school, but I was raised to believe you don't screw over people just because you can.
How exactly is it screwing someone over? That would imply that they have some initial claim to my property and that by not giving it to them at their desired price, I'm slighting them. You're looking at this from the wrong angle.
Here's the correct starting point: I own something. It's mine. I will keep it if I choose. On the other hand, if you can make it worth my while to part with my property, you are free to try. If you are unable or unwilling to do something that I deem worth the trade, it will just stay mine. And someone else may come along and do what you were unwilling.
There's no such thing as an "excessive price". There's the price I am willing to part with my property for and there's the price someone else is willing to pay to get what I have. A sale happens where those two prices meet. No one is being screwed. It's just an agreement between two adults to trade value for value. Anyone not participating in the sale has no say in what is right or wrong about it.
Would you hire me to mow your lawn every week for a year for $1,000,000 total? No? Are you unable or unwilling to give me that much for mowing your lawn? Would I be screwing you over if I demanded that much for mowing it? So don't hire me.
Would you hire me to mow your lawn every week for a year for $1 total? Are you concerned about that fact that it would then be you screwing me over for paying me so little for something of much higher value? Would you be taking advantage of me? If I think so, I won't let you hire me.
How do we settle this? If I charge too much to do it, I'm screwing you over and you don't want the deal. If you pay too little, you're screwing me over and I don't want to make the deal. How about we just find the highest price I'll work for and the lowest price you're willing to pay. If the two prices match, we have a deal. If not, we part ways.
Sounds familiar.....