Here's why the invoice price is only "roughly" what the dealer paid for the car. It's because of the "holdback" amount that most manufacturers assign to a car. The holdback is a percentage of the sticker price or invoice price. Manufacturers pay it to the dealer after he sells a car. This means that a dealer could sell a car at invoice price, tell the customer that's he not making one penny on the deal and still get a check from the manufacturer a month later for $500. For more information on holdbacks and the holdback amounts for the different manufacturers, see this article.
True Market Value (TMV) Price: Edmunds.com created the TMV price to be the one car-buying number you need to know. Edmunds analysts look at the market, examine what other cars have sold for, consider the popularity of the car within your region and set the TMV price. It is the average amount that other buyers in your area are paying for the car. Usually, TMV is less than sticker price but more than invoice price. Because it's an average, some people will pay much less than TMV and others will pay more. But by looking at TMV, you can get a rough idea how popular the car is and what you should expect to pay for it.
Kelley Blue Book Price: There's one last term car buyers often hear and that's the Kelley Blue Book price or, more simply, a car's " blue book value." It's important to understand that these two terms mainly apply to used-car shopping. Kelley lists its own used-car values, using its own method. Often, Kelley's prices differ from Edmunds.com's TMV prices. Dealerships will use Kelley prices when making offers on cars people want to trade in or when they're listing used cars for sale on their lots. For more information, read this more detailed explanation.