Try the neutral safety switch on the clutch pedal. Sometimes they get sticky. Mine has done it since the day after I picked the car up off the lot albeit intermittently. Pumping the clutch a couple of times before I start it is just habbit now.
But you can get into the footwell and check it out see if he cut/vampire tapped the wires to the neutral safety in an effort to put in a remote start or bypass the safety on a dvd player.
Also test your battery. Auction cars sit a very long time, long enough for a cell to go dead. Should have at least 550CA. My last battery that went bad would still start the car with 300Ca but the no start problem was more prevalent.