Maybe it makes more sense with shovels. I approached a local hardware manager with the comment, "Your competition is selling shovels for three dollars less than you are". He suggested I buy one from the competition. I said that I would have but they were out. The manager said the he would list his for three dollars less when he ran out.
A dealer can show any lowball prices on "Sold" units, since they do not have to match it today. I am not saying that it is impossible or illegal, just be careful out there.