If you don't accept the sellers' counteroffer exactly as presented, but instead want to make changes, then it's a totally new offer from you—a counter-coun­teroffer, so to speak. You want to make this counter soon, usually within a day, while the sellers are still psycholog­ically engaged in the deal.

While it's usual to limit any offers (or counters) by a time period, once you're into countering back and forth things tend to fly fast. I've seen these counters come whizzing one right after the other, either by fax or carried by hand.

That doesn't mean you shouldn't put a limit on the time for acceptance of your counter. If you don't, then the offer is open until withdrawn (by you) and at any time the sellers might say, "Let's just pull back and wait a few days."

That's why I always suggest making any counter for as short a time as possible, often 24 hours or less. This puts the sellers on the spot. They must act, which is exactly what you want them to do. (Remember, there's always a chance another offer could come in from other buyers and torpedo yours.)

It's worth noting that there are certain tactics involved in negotiating here. If you receive the sellers' counter and then immediately counter back, the sellers may think that you really haven't taken the time to seriously consider their previous counter. Or, they may feel that you are very anxious—countering so quickly. They may feel that your most recent offer isn't your best, and your quick counter may cause them to hold back from accepting it, perhaps countering you once again.

It's for this reason that I will often hold back a few hours, sometimes as much as overnight, even though I've already made my countering decision. I want the sellers to think that I'm considering their offer very carefully. I also want them to consider that perhaps I'll simply reject their latest counter and walk away, which is my privilege. In other words, I want to keep the sellers off balance. It's better if they think they've got a finicky buyer who might just as well walk away from the negotiating table as stay and continue to play the game. This encourages the sell­ers to take fewer chances and to make each of their counteroffers as good as possible.