Should I replace the starter/solenoid?

I have a 99 VW Beetle, Automatic. Yesterday we had a problem where the car wouldn't start. The radio and the lights came on but the car didn't even crank. It just made a noise like it was trying to pick up but couldn't. We thought maybe we should replace the starter/solenoid. The only thing is that for the last couple of weeks the emergency brake kept beeping and coming on flashing. This was happening off and on. And just recently the lights sometimes blinked a little. So we didn't know if maybe it was related to the car not starting or not? What does everyone think? I don't want to spend the $120 on the starter/solenoid if that doesn't fix the problem of it not starting.

Two things I'd check which may be unrelated - first is the stoplight switch on the brake pedal ...and the second is the fuses on top of the battery which can corrode and short out. Also check the battery terminals which should be clean and tight. Sounds a bit like a bad connection somewhere. I don't think the starter solenoid is the problem from your description.
Good Luck.