I'm looking at getting a TiVo, but the new Series 2 models are ring-a-ding-a-doodle expensive. I was thinking about buying one of the low-end models of the first Series off eBay, then upgrading the HDD. Looks like I could get one with an 80gb drive for around 200 bucks. Your thoughts on that? Also, what do you think are the advantages/disadvantages of Series2 over the first? Does anything make Series2 a must have for that price?