Something most people overlook is dealer overhead in their markups.
In my case, the cash and interest incentives are from the manufacturer, not the local dealership.
Negotiation is really about the dealer 'markup' over 'true invoice cost'.
Personally, I am willing to pay a bit more for dealers or salesman that take good care of me and have the resources to support me. 3 Massey dealers were nice enough but, could not talk about a 5700S/5S beyond what I could read off the brochure. The dealer I am working with actually has this tractor in stock and can service it and I won't be the only one at the dealership using the service department to fix it!