I've built a MythTV home media PC, attempting to keep the costs down. It's already cost $539, which is more than a Tivo HD ($299), and very close to a Tivo Series 3 ($575). The advantages over buying a TVIO include:
- DVD / CD playback and archiving to HD.
- Cheaper subscription costs (Free over the air, or 20-40$ a year from Schedules Direct).
- Automatic commercial detection.
- Open Platform, which allows for easy network mounting of file-systems, administration, and customization.