In this economy, it's especially important to spend your money wisely. This means you shouldn't hesitate to haggle where appropriate. Wired Magazine explains how changing perceptions can help you score better deals.
Photo by maveric2003.
The magazine tackles the topic of haggling on Craigslist, but their advice can easily be extended to the offline world. Specifically, Wired suggests to only lowball if you have a solid rationale, and not just for lowballing's sake. In general, it's best to follow the "principle of market psychology": fairness. This requires changing the seller's perception of the exchange at-hand.
The fact is, many sellers would rather hang on to something they no longer use than accept less than they think it's worth. In that light, negotiations aren't about besting the seller, they're about finding agreement on what's right. Therefore, a good negotiator works on changing perceptions.
The fairness principle should also extend to any counter-offers you make, which Wired says should never include phrases like making "an offer you can't refuse".
Hit up the full post for other haggling tips including why it's best to negotiate in person.