As a seller I might add a bit of wiggle room in my pricing.
As a buyer my first offer is not necessarily (and rarely is) my max, call it negative wiggle room if you will.
Sellers should be motivated to make a sale and unless the price is listed as "firm", I would assume that their asking price probably is not so firm.
I would maintain that the assumption that the buyer's first offer represents the max he is willing to pay is fallacious much of the time. A non-negotiable buy-it-now coupled with a non-negotiable sell-it-now with two different numbers is a waste of time, like looking at all those outrageous BINs on eBay.
To walk away from a deal at this point without counters virtually eliminates a deal that both parties would gladly accept. If that happy medium is not reached, either party may walk away at any time, but that party should notify the other that that is their intent.
Haggling is not a disease or a waste of time, but a tool of free market economics.
That said I realize there are many who prefer to eschew negotiation, which is their right, but unfortunate in my opinion, unless of course as a buyer they simply say "I'll take it".
