Cheap jewelry can detract from your look, and too much jewelry can do the same. Having a few subtle but well-made pieces, or one prominent one that is your centerpiece, will do far more than loading up on cheap jewelry. You also don't need to get very expensive jewelry as well. Keep it in your price range, but with a budget of $100 I'd recommend going for a few very nice things you like (ie, a single necklace and a pair of ear rings), instead of trying to get as many things as possible for that $100.