Which Brands Can You Price Bargain with?

I am looking to a buy a laptop--probably a Lenovo Thinkpad T-Series, Dell Latitude e6510/6410, or HP Elitebook 6540/6440.


I have heard that with some brands like Dell you can bargain on the phone and get a better price/deal below the listed online price?

Is this true?

And can you bargain with Lenovo, HP, or other brands to reduce the price?

Thanks.