I agree with what was said BUT
While maintanence is by far the most important issue you can never really be sure what was done and what the owner said was done. Sure you can do a detailed look over but just because fresh oil is innow does't mean the oil that was just removed didn't have 30,000 miles. So absent things you can check i.e. general condition the only thing you can be sure of is the year and the mileage
"Take it up with my butt, cuz he's the only one that gives a crap"
Carter Pewterschmidt