You'll get more for your money buying from a private seller. However, I prefer going the dealer route because any reputable dealer (or less shady dealer if you believe there's no such thing as a reputable dealer) will have their techs inspect the vehicle and do a few maintenance items like change the oil as well as clean up the car inside and out. Unless you buy from a extra shady dealer, you're less likely to end up with a car with problems that the seller has tried to cover up. Once a private seller has your money and signs over the title, he could care less what happens beyond that. A dealer probably doesn't want the bad publicity associated with misrepresenting the conditions of the used cars they sell.