If you have cable or satellite, you can "rent them" by subscribing to their HD package. If you just use antenna (who buys and HDTV to watch antenna?) you can buy a stand alone box. They are still relatively expensive. Its a shame to have an HDTV and not watch HDTV on it.
When a TV says it is HD ready but does not have an HD tuner, does that mean you have to purchase an HD Tuner? Or is an HD Tuner something that is provided to you by your cable company? If it is something you purchase how expensive are they?

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