You can try to (trust me) hit the starter with a hammer and then try it. If it starts... buy a new starter, or a chrome hammer.

I have tested the starter before on my own. Just hook a battery up to the pos AND the little terminal, and the neg to the body of the starter. You can just do this on the driveway. It may jump a little but don't worry. You can tell if it is intermittent with this test.

Buy a used starter for $40. My original lasted 400,000 with many starts per night as a pizza driver.