Why pay $299 for a new HD TiVo Premier when you can get a "factory renewed" unit for just one c-note? It comes with the same warranty as a new unit, and ships for free, directly from TiVo. My first TiVo was a refurb unit, and I haven't had a single problem out of it for three years, even as it's been moved to three different homes in its lifetime.
Also, if you want more storage and don't mind getting your hands dirty, pick up one of the many affordable hard drives that appear here on deals.woot practically daily, and then upgrade it yourself, using the tutorial at http://bit.ly/tivoup. I recommend you get one of the "energy efficient" hard drives if you want to keep things cool and quiet.