Depending on your traffic needs, you could have a host for $10 or so. The more traffic you get, the more bandwidth you'll need. This will require a host or hosting package that is more $$.
Downloads would depend on the website. If it's already available for free (legally), then charging for the program would likely be illegal and most people wouldn't take kindly to that. The loophole around this would be to have a capped free download system, and then a paid, uncapped subscriber.
However, you'll need to be competitive in pricing.
Banner ads and Text links are two forms of advertising that go by the pay-as-you-click rule.