There are tons of polite openings to negotiation:

"Is there room on the price?"

"Do you have any offers on this item?"

"What's your best price on that?" One time a mattress salesman responded sarcastically with, "The one on the tag." So, I said, "Thanks." and turned to leave. He called me back immediately with a lower price. I still left and bought at Costco, instead, since the price was dramatically lower even without negotiation, and I don't like snarky pushy sales people.

Another mattress guy once challenged me with, "Are you going to shop around more once I tell you our best price?" And my reply to that was, "Of course." And he said, "So why should I tell you our best price now...come back once you've gotten prices from the rest of the stores you're going to talk to, and I'll try to beat it." My reply to that, of course, was, "If you don't give me a price better than what I'm seeing on the tag before I walk out that door, you will never see me again." He, too, offered a lower price. The lesson in this is that salesmen tend to understand that the only person who can really say "yes" to the deal is the customer, and they've only got one shot at that yes. They do a lot to try to avoid having the customer frame it in those terms, because it's a powerful position to be in. You need one item while they need many sales each day, and you're one possible sale.

If those lines are still too confrontational, just say, "I really like this one, but I'm afraid it's out of my price range..." and let it hang. Most people can't stand silence, so if you give it 30 seconds, they'll probably come back with a better price. Higher end negotiators will know that speaking first when it comes to points of the deal nearly always gets you into trouble, but sales guys at Best Buy almost certainly do not (some sales guys are instinctively really good at grasping human nature, and know this stuff without being told). Car salesmen generally know these things, so you have to be particularly vigilant when dealing with car dealers.

A few valuable things I've learned from growing up at flea markets and garage sales (my mom is an antiques and collectibles dealer, and I was her muscle when I lived at home):

- No object you're shopping for is precious or unique. Do not get attached to specific items. There are many more just like it or better, in other places, and other times. View it as something you will someday throw away or donate to Goodwill, and you can view it more rationally. That beautiful iPod? In five years it will be trash, and in three you'll probably replace it anyway. In short, always be ready to walk away from any deal.

- The deal of a lifetime comes around about once a month. If you're being pressured to buy right away, it probably means buying now is better for the vendor than for you. You should think it over. Reject aggressive time pressure and exploding offers without even thinking about it; if a salesperson insists you buy today to get a specific price, it's likely another store has the item for cheaper and he doesn't want you to price compare. Regardless, you are at a severe disadvantage if you allow the salesperson to set your schedule for buying. You can turn that around, however, with, "If I can get this for $X, I will buy right now." Salesguys really believe in "bird in hand is worth two in the bush", and will do a lot to get you to hand over your money right now.

- Know what you're buying and what you want to pay for it. Knowledge is the most valuable thing you have in a negotiation. Keep as much of the advantage on knowledge as possible to yourself. If you know you can't order online because you need an item right now, never say that to the sales person. As far as they are concerned, you might buy today, or you might buy next month (until you need to use the "I will buy today at X price" gambit), or you might not buy at all. Corollary to that, however, is the fact that good sales guys can smell money and a willingness to spend it. They may not take you seriously, if they think you're just being a lookie-loo, and won't give you their best price without the hope of getting your money today. Don't feel bad about the knowledge advantages you have...they have more such advantages on their side. They know the wholesale price, all available offers, whether it will be on sale on the weekend, etc.