Key will not unlock door remotely

It has to be done manually with the key and buzzer runs for while after cranking the engine.I'm looking at a 2003 2.0L 5Speed w/118K miles. Runs and drives good. The owner doesn't know when the timing belt was replaced. He bought it from a first time owner at 92K miles.

The driver door has to be unlocked manually with the key and when I got in to crank the engine, I had to reset the key once even though I had the clutch in and the brake on. The buzzer continually goes off and then goes off. The owner said it was the door switch.

I noticed the little door light down on the lower part of the door was upside down which may indicate someone had been in the door panel looking at the circuit. I don't know anything about these beetles. The car seems to be in good shape. I don't know how expensive this might be to fix.
Thank you,
Jeff