Leasing things that are already up there and have downtime is going to be a future possibility. I don't know about cheap though. No idea. Dynamics like Moores law will make it possible at some point. It's a general hunch.
> No. Laying fiber across neighborhoods is extremely expensive.
Which means, yes, it is a perfect opportunity for entrepreneurial activity. Extremely high, prohibitive costs means a new, cheaper, scalable way of doing things would be disruptive and have high reward
Yes, some towns have created their own municipal fiber optic networks, but it's done on a small scale.