No Openreach GEA Fibre presence on your exchange, and my bet is on it coming from Cranbrook if they were to quote. In which case quote is fairly cheap
So how do you know this ia an Openreach fibre? Location suggests might actually be some Callflow fibre strung up on Openreach poles (duct and pole access means this is possible). Or there may be a business with a leased line.
Even if not Cranbrook then the other likely locations are roughly same distance anyway.
Getting more of the other slow properties on the road to increase size of CFP may reduce the price per property i.e. overall cost would go up but split equally individuals might pay less. Enlarging to cover a business or two with their larger vouchers would help too.