Well, remember there are other expenses: the antenna (which could run a bit depending on how far you are away from what you want to receive), plus some sort of HDTV receiver. And if you want an OTA HD DVR... well right now there aren't many. There's an older LG that lots of people have had problems with, and the Sony which was generally better is now discontinued (after like only 8 months). Hopefully more coming out later this year, the TiVo keeps threatening to release an OTA HD compatible model.

Beyond that, if you mainly watch the nets anyways, then yeah - OTA is good and cheap. Plus, it's the only way you can get HD programming in its absolute best unreprocessed quality (and I will tell you that OTA looks better than cable and much better than satellite).