Well the way I look at it I would offer the guy $500 and he is also throwing in a set of 16" rims, which i could sell easily on ebay for $100 that would leave me with a $400 investment even if i had to invest a couple hundred to get it on the road it would still be one hell of a deal. Worst case I could always part the car out for $400+ easy
I just dont see it as being any major problem causing the car not to fire. Only parts i can thing of would be: plugs, wires, cap, router, battery, sensor, fuse, injectors, or pump. None of which are very expensive. Can you think of any other parts that may be causing the problem.