The problem I have is that you seem unwilling or unable to grasp the simple fact that you had agreed to sell the gun to me by post number 3 of this thread.
As far as I am aware, this forum does not make it a condition that you find out where the seller lives before you agree to a price.
Your argument relating to me "belatedly asking you where you live" does not make any sense, particularly as you had already told me that you work as a delivery driver and so would be able to meet me at some mutually convenient location.
The facts are that, after agreeing to this sale and then rearranging everything with me via PM, with you then take it upon yourself to sell it at a higher price to someone else, while at the same time arranging to meet up with me via PM.
Agreeing to one thing and then doing another is not what the "For Sale" thread is for.
All the Mods need to do is to check your PM's to me, then compare those to the thread.
As I said, you need to get your argument clear in your head - if you have one - before you get involved in one.