That's fair enough, nobody's saying that you can't sell something for a profit, though. My issue was his double standards, on one hand saying he was only selling to do a favour/good deal to a fellow forum member.. When the reality was he was looking to make a quick buck from me.
The fact is, if he had been honest from the start I'd be cool with it. The fact he wasn't leaves a sour taste in the mouth.
In any case, he was selling something used for more than you could get it new, and for more than he bought it for new. A Sony 55mm FE is not an appreciating asset, or a collectors item.