Halfords say :
"If you find a cheaper price we'll match it, and if you find it after you've purchased from us we'll refund the difference within 7 days of receipt of your goods"
So far £1700 is the lowest I have found and that is Halfords with a discount.
Thanks for all the good advice. I am not sure how Halfords could justify selling an e version of £300 bicycle for nearly £1900 list, £1700 discounted price but I guess the simple answer is they can