How can it save you money in the long run? Its about $4 more a month service wise then the cheapest box is $150. That's a years worth of DVR service without taking into account the $14.95 a month.
This is not taking into account the TiVo becoming useless if cablecard stops being used and having to get a new box.
Cablevision is working on downloadable security which may do just that.
With the TiVo you have residual value. A TiVo with Lifetime service has a high resale value. So at some point down the road you can sell the TiVo to cover most of the cost to upgrade to a newer model with lifetime. I've gone through over eighteen TiVos during the last seven years. Each time selliing my older lifetime boxes for newer ones. The sales of the older boxes covered around 80% to 100% of the cost of the newer lifetime boxes. If i had been using FiOS or Comcast DVRs during that entire time, I would have spent much more money.
Which anyone buying an old use box is just crazy when going out to buy a brand new box that is current. It's like buying a 5+ year old Mac for the price of a new one. people think the resell value is there when in fact it isn't. Also make sure you note that Tivo uses the Internet to update itself. So anyone that has a capped connection gets to take that into cost as well.