Some Web hosts charge an extra fee if you go over the plan's limits. And because of the heavy bandwidth requirements, you may have to pay extra for support for streaming audio and video. Most companies provide free CGI-bin support, but you should check if you plan to use CGI scripts. Though price is important, don't forget to balance considerations of price with the features and reliability that you'll require. If your needs are simple, you can shop for a basic set of features at the lowest price.
Reliability is difficult to measure, so it's even harder to shop for.