I am in the process of purchasing an HDTV. What are the advantages of having a built in HD tuner? How much does a HD tuner cost?

A built-in HD tuner allows you to receive over-the-air (OTA) HD broadcasts with an antenna. If it is capable of receiving QAM (digital cable) signals, it also allows you to receive unencrypted cable HD channels; this usually means just the local broadcast HD channels that your cable company carries, plus maybe a few odds and ends.

(note: QAM is digital cable, ATSC is digital over-the-air; they use different protocols for transmitting the signal.)

If you will receive all your TV via a cable or satellite set-top box (STB), then you don't gain much by having a built-in HD tuner in your TV. But all new HDTVs have to have them anyway, except for units called "monitors" and not "TVs". You probably won't save much by buying a HDTV without a built-in HD tuner, unless it's a leftover old model. And if you want to add an external tuner in the future, it probably won't be cheap. The only widely available external HD tuner right now is a Samsung model that costs around $180. I don't expect the price to fall significantly because it's a niche-type item now that all new HDTVs have to have built-in tuners.

Can you modify the title of the thread? "Help" isn't very descriptive. :rolleyes:
Thanks!