For that model I don't think you will see a noticeable difference in price. Look for an 88 1/2 year if you can afford it. The one advantage to a dealer, assuming they are honest, is they will have inspected the car with their mechanic. Otherwise it would be wise that you have a car inspected if you are buying from a owner selling his car, in which case you will have to pay.
I would recommend going both routes at the same time. Then you will be certain to not limit yourself and you'll end up seeing more cars.