I have comcast internet with my own modem/router. Comcast will not give me a static IP unless I use their rental modem/router, which costs quite a bit monthly. I use ddns to work around this issue, and it mostly works fine.
I also don't have a static ip at home, but have a hub-star private network that runs over Cisco routers over the Comcast network that allows multiple employees to share in the resources, from the single connection with public facing IPs, with pretty low latency through the private network. It's all done on the cheap, but fast enough I can remote into the office and work on 3d models or photoshop. Certainly fast enough for routing side projects for testing. Obviously this is more complex and costly than the initial home setup of a single node. But even in more rural situations it should be easy to build up networks of like minded people with local ISPs which could share resources like this. Apply for /24, get it setup with an ISP, and then VPN the rest of the traffic in from fellow customers.
I agree with this. Comcast, is certainly not the cheapest option. We pay right now around $220/mo to have our /29 addresses routed through Comcast. It was about half that over bonded channels of VDSL. But these rates may be a non-starter for a home setup. But it still seems pretty low cost, given what I hear from most of my friends about what they're paying for Cellular plus Home-entertainment on a monthly basis.