"I'd prefer not to have to pay the dealer's profit margin though, and that's where the ethical question comes up."
Cadet,
If everyone took this approach on all that we buy we wouldn't have any places to purchase any of our needs, there would be no stores to shop at. Don't know what you do for a living but if your employer couldn't make a profit from his business you would have no job.
Try and work a deal with him that's fair for both of you. If you go the other way, expect nothing from him in the future, and expect that at least some others will learn about it.
