Re: good starting point
Split the cost between the telco and builders 50/50 and you are also laying the ground to get the surrounding areas up and running to fttp.
You are joking aren't you? If the builders contribute to the cost that contribution will only apply up to the point at which the property is sold to an occupant. And the telcos will (perfectly reasonably) need to recover their investment, so guess who pays for that? Yes; the occupant, who will probably be forced to have an FTTP service (assuming that they want broadband in the first place) even if its performance far exceeds what they actually need.
How would you like it if you went shopping to find that only top of the range goods were available on the grounds that "some people want it"?