> good negotiator might be able to get a lower price than someone else.

A good negotiator is worried about more than price. There is quality, time to get the product, support. An lot of other things on those lines that I can't think of at the moment too. A good negotiator knows what is important to them and how to make the best trade off for their situation. Sometimes a good negotiator will offer more than the asking price because they know those others are important and if the company goes out of business they get none of them (this is rare, but it is sometimes needed).