The way it worked for me, there are certain dealers that are Costco partners. You get a price for the vehicle you want, take that document to the dealer, and in theory you're done. No negotiating necessary. But, I think you could get to the same price if you went to the effort on your own to negotiate, check out other dealers, etc. I'm not even sure the Costco price was "the best" based upon what I was seeing, but it certainly simplified the whole process in my experience. Now that I think about it, I found another dealer that would match the Costco price. I did this about 9 months ago, so I'm not sure if things are different now. And it definitely didn't take out the extra add ons that the dealer tried to sell - still had to say no to that stuff.