Openreach have announced that their installation fee (to the ISP) will be a minimum of £500, and may be up to £3500, depending on the distance to the cabinet. I suspect a proportion of that will be swallowed by each ISP in return for a minimum contract.
Apart from a few trial areas, I'm not aware of a general roll-out of the service by BT yet. Somebody else may have more information.
FOD is being released on the 26th to ISP's, I would expect BT to sell it on the day or at least within a week.
If ducting is needed the price goes up. More work, more money. No space in the existing ducts and you would have to foot the bill for more ducting, unless openreach saw it in their best interest to pay it themselves for future capacity.