It is really bad to have this kind of situation happened to merchant. Even though no money involve, but time wasting is consideration a loss to seller as well.

I do hope people will get more cautious before approaching buyer. Do not just come and say , "bro, PMed me with the best price, interested buyer here" while you know yourself the price even though lower a bit will not suit you in the first place.

I hope the guy apologizes to seller for his act that cause uncomfortable feeling to seller. That way is much ethical.

Cheers and Peace.