I've been a Tivo user, on and off, since 2000 (I would switch between DTV and cox for football season). I just started using my Series 3 with lifetime again and yesterday I order a XL4 from Tivo on a special where they added the usb wifi device.
I called today and asked about the minis. They told me it's $99 per with $149 for lifetime.
I told them Amazon has it with two day shipping for $79. I was told Tivo could not match that price.