The rentals equal out the cost of a new ARRIS SURFboard SB8200 in about 10 months. After that, your modem costs are free. In 16 years, I have purchased 4 new modems (always for purposes of updating) and had zero issues. Figure an average of a year of rental fees to pay off each of the four modems, and the result has been 10 years without the $14/mo fee, a savings of $1,680
People who live in areas that are susceptible to having problems can always add the additional service fee to pay less for visits. One caveat is that your self-purchased modem needs to be on their current/approved list, i.e., it cannot be outdated.