This happened to a friend of mine on the other forum and I wanted to have your opinions about it.
Gentleman 1 is selling an airgun
Gentleman 2 wants to buy said airgun (pretty easy to follow up to now huh)

Buyer contacts seller about the gun, seller informs him it's already sold.
A little while later the seller contacts the potential buyer offering the gun to him because the original buyer is a no show and states a price for the gun.
Potential buyer ask if he may get a small price reduction.
Seller doesn't want to lower the price of his gun so sells it to a third buyer.
Now the second buyer writes back asking what is happening with the gun.
The seller informs the buyer he didn't want to lower his price and sold to another gentleman.

See anything wrong here? Should the seller have contacted buyer number 2 informing him he didn't want to lower his price before selling to buyer number 3?
Can you guess who I am errr I mean my friend... is in the story?