e28 wont start

http://raleigh.craigslist.org/car/448076369.html

im interested in buying that if its a cheap fix, but im not really much of an expert when it comes to diagnosing car issues, my guesses are a bad battery, a new starter, maybe it needs new circuitry, i dont know, does anyone have any ideas? i mean i know its a pretty vague description of the problem but i want to go buy this car like yesterday if the fix is less then 200 bucks