I'll give you a short story just to set expectations of what this might entail.
About ten years of so ago (just to give an idea of how much the prices will have changed), I had a client who were based in a really nice converted set of farm building in Kent. Lovely working environment, quiet, you could take your lunch out into the attached fields, lay down and watch the kestrels. The problem of course was internet connectivity, now although you could literally go up onto the roof and see the nearest large town, which did have good connectivity, they were quoted half a million pounds to have fibre laid to their site! I remember talking to their CEO who asked me what could be done, and I said, 'well frankly Jane, you need to move the company to Docklands! Other than that, you need to put up with what you have'.
The cost is the digging up and making good afterwards, not the cost of the fibre itself, which is pennies. In the case above it meant tearing up a lot of farmer's fields and crops, it being all arable, who weren't happy about it, and absolutely would go legal on it.
So based on that, what might it cost VM to dig up the roads and pavements to provide connectivity to you when they can't be sure of ever, ever getting that money back?
If Openreach have no immediate plans to install FTTP in your area then that probably says something about the circumstances in your area - have you considered moving?