Does anyone have any insight on what it takes to start a new ISP (like Comcast, but at a smaller scale)?
Do you need a significant amount of money to even get going and lay your own infrastructure? Or are larger companies like Comcast required to sub-lease their lines to smaller companies (so they don't have a monopoly).
It's going to cost a ton no matter what. Infrastructure aside, the networking expertise you're going to have to pay for is significant. Plus the costs of marketing, sales, and installation equipment, crew, & training.
Some Tier-1 networks do sell access to their infrastructure. A couple are:
An option to build your own infrastructure could be to work with the city government, and see if you can get state & federal grants. Here are some news stories about small towns doing this; some of the cost details are illuminating:
Most of the local ISPs are actually hooked into Level3. You can think of them as the "ISP for ISPs".
Here's a relevant question that might be of some use: