The clicking would make me guess low battery. When it does turn over is it really slow, or does it turn over like you would normally expect it to? As far as testing a starter, I had one acting up so I pulled it out and took it to AutoZone, where it turned out it was bad. A re manufactured one was around $50 I believe (this was about 8 years ago, though). As far as testing one while still in the car, I don't know if that is possible or not.