You can call Tivo and see if you can get lifetime for it at $99 or $199. Resale value increases with lifetime then without.
You can then get either a Roamio 4 tuner, any Premiere 2 tuner, or Series 3 models.
Original S1 (Recycle Heaven)
Series 2 (PLS, sold)
TiVo HD (XL, PLS, "652")
Juliet Basic (4XL, PLS)
The TiVo Apocalypse begins on Sat 2013 Feb 16 00:00 GMT!