This is a customer to customer help forum, no one from Comcast is reading this to answer your questions about options. You will either need to call or go to the blue SHOP tab and see what deals would be available for existing customers.
The Xfinity thing is just a branding name change for Comcast services. Comcast internet service alone generally costs more than if you added another service with them. In my area if I did not have tv service with the internet it would cost me $15 more per month for the Internet than what I pay with the TV service.
I keep Limited Basic TV service just to keep the Internet price down.
