I found a quote on Slashdot form a user going by the name pete6677 that sums up the truth on negotiations:
This is what’s wrong with refusing to walk away from a deal. You have no negotiating leverage. When the other party knows you’re committed to buying no matter what, they have no reason to accommodate any request of yours.
They key is letting the party you are negotiating with know you’re willing to simply walk away if some of you wants aren’t met. The story this was posted in deals with the iPhone and the abuse of users by Apple and AT&T. Both companies know most people who are getting iPhones won’t walk away from any deal put in front of them, they want that phone period. Because of this they don’t allow many features people would find useful such as tethering and multi-tasking.
Never walk into any situation where you want to buy a product and allow the salesman to believe you aren’t willing to just walk away. I got some hefty discounts on my truck simply because I had a list of features that I knew none of their trucks had but their competitors did. Since they didn’t have anything with those features they gave me some discounts to make up for it.
This is also an important strategy when going to gun shows. Never purchase anything from a gun show without trying to negotiate a little bit. Many sellers will cut the price a bit, after all there is no guarantee somebody else will buy the item. This usually works best if you got to several gun shows and notice the seller has the same gun for sale at all of them. Likewise if you’re willing to pay cash often the sellers will cut you a bit of a deal as well.
Obviously haggling doesn’t always work. You won’t be able to walk into Target and negotiate the price of anything. But if you are dealing with a salesman who gets paid off of commission you generally have a good chance of netting either some discounts of free upgrades. The key is to make the salesman know you are willing to walk away.
Knowing how to barter is important, it can save you a lot of money over your life time.