Not to defend this guy as I believe the ad is quite funny as well, but ignoring lowballers simply saves your time.
If I'm selling something for $500 and you offer $250 or less you simply get a no thank you, no further contact from me will be made, and 0 attempts at negotiating. Why? Because from there it has never turned into a deal being made, so why would I waste my time?
Nothing worse then a guy who expects you to answer 100 question, 1 question at a time, to lowball you in the end so far away from your price that there is 0 chance of a deal.