Gentlefolk,
One is tempted to suggest that BT are hiding the fact that their lines are of poor quality in the area and the price reflects (at BT prices) how much aluminium and copper requires replacement.
The road distance is 3.01 miles or 4.84 Km according to Map24 which, if an accurate estimate of the actual line distance, ought to provide a slow but reliable ADSL connection on a reasonable quality line.
Kind regards,
Walter