3 Things:

1) No big deal about the card. You have to get a new card when you get a different receiver anyway and DTV will send you one ($25 bucks or so).

2) Be carefull about the units on Ebay that say they are "in a retail box" or somehow imply they are NEW. I bought one of these units and it was in a retail box, but it was FAR FROM NEW. The user I bought from was a guy called "whiteport" and his auction description would lead you to believe that his Tivo's are new, but they are NOT. Don't get F'd while trying to save a buck. I've found that the units are available from your local Good Guys, Circuit City, Target, etc.. for just about the same price. The piece of mind buying locally where you can return it if needed is worth a few extra bucks anyway.

3) I recently heard that DTV was offering a Tivo upgrade to current subscribers for $159. You have to check it out for yourself, but I think that's a real offer and a real deal if it's true.

FWIW - The series 2 units (HDVR2, DSR7000, etc...) will not accept an HU Card, so if that's important to you then you'll have to get a series 1.