Because demonstration vehicles are often sold at or after the model-year end, incentives and rebates are hefty. You can purchase a demo model with thousands off and often at a low interest rate for financing. For example, you might receive a $4,000 discount and zero-percent financing, an attractive deal for a vehicle that is still considered new. Many buyers are satisfied with the attractive amount of money given off by the manufacturer in addition to low finance rates.
If you buy a vehicle with incentives and rebates alone, it might seem like you're getting a good deal, but the dealer is still making maximum profit from the sale. Incentives and rebates are reimbursed to the dealer by the manufacturer. Because you are buying a car with mileage on it already, you should pay a reasonable amount under the dealer invoice amount, at least $1,000 below, in addition to rebates and incentives.
You should pay at least $1,000 under invoice before any rebates for a demo vehicle, which the dealership knew was a loss the day it was set out as a demo. The dealer should discount the vehicle accordingly, although he may try not to unless you ask. Use Edmunds, an informational website for vehicle shoppers, to determine the invoice pricing.