You can certainly get a camera for under a hundred. Will it be good? Sure, if you don't want digital. If you want to go film, you can definitely get into a moderately high quality camera for that price point. Digital though you're going to be on par with cell-phone-cameras and webcams.
For a decent entry-level digital plan on around 300 or so, maybe more maybe less depending on the model and features. To get really high quality tank shots you're looking more into the 500 range, and to get pro level equipment you're over a thou.
Of course that's all just roughest of rough estimates. You can buy used, ebay, sales, etc.
Digital = Instant Gratification. You know immediately that you got the shot and you can make those slight adjustments if needed. I used to shoot film on SCUBA vacations, and there's nothing worse than getting home before you find out that picture of a lifetime didn't come out! For what it costs to process film, then digitize the ones you want to post online, your already ahead. Save your dough and shop around. Compare prices online, etc. Also, get a USB chip reader for your type of camera. It makes the downloads way faster than using the cord.