Xfinity has a list of compatible modems on their website somewhere.
Xfinity pricing is bizarre. All I wanna do is exclude all the premium channels that are bundled including a Netflix subscription I don't use I make an effort to do this they say they're gonna charge me overall $50 more per month. A substantial increase just to reduce the level of services.
The equipment charges along with those broadcast fees are getting quite crazy.
Price and I do have a separate modem and router that I don't have to rent but they do have compatibility issues so you need to check very carefully.