I would not go below $4k, are you mechanically inclined? if not you want to leave room for repair costs. overhead cam engines have to have timing belts replaced and usually the water pump is in there too...can be expensive. Cars with pushrods do not have this expense. then you don't know when the timing belt or if ever was changed on a car w/ 120k+ miles. Get a car that has passed inspection for your location. look at the dip stick if brown its varnish from never having the oil changed. see if they have maintenance records for the car. see what stations the radio buttons are tuned to, rock , pop music probably no to little maintenance done on the car.