yeah, everyone wants a good deal, just keep in mind, that sales person gets paid based on the profit the dealership makes. if you get it down to the dealership cost then that sales person won't make any money. Maybe 25 bucks depending on the dealership. Example with the whole adding in stuff to make the deal better. To add a sunroof to a car is something like 1,500 bucks. Do that to a new Altima, and the sale's guy doesn't make anything.
Just something to keep in mind when you're trying to get the price as low as possible. The dealership will have their minimum profit built into the price, and it won't go below that. The sale's guy is the one that gets nailed when you haggle the price down to "cost"