Compare what the used car dealer offers to what is being charged by the seller. If it's less than the price you are paying, then it's a great deal. Keep in mind they will try to buy it for the lowest possible price. When a dealer buys a used car they will pay only what they believe is the wholesale price. What they offer you will be based on how your car looks, not only the mechanics.
Image counts the most.
Once you've found the car, it is likely you will need to finance it. Financing is another product to buy. Unfortunately, banks, credit unions and car dealerships take advantage of used vehicle buyers by charging a higher interest rate on financing used. Yet, they will finance you at a lower interest rate for five or six years on a brand new car. In addition, your interest rate will be lower on a new car.