Sorry to jump in here, but whenever I've insured a new bike I have always declared all the extras and stated the invoice price, including any extras, even if bought elsewhere, as the full value of the bike. I do this knowing that if the bike is a total loss in the first year (or six months on some policies) that the insurance would pay this figure, minus the excess, or replace the bike like for like.
In 2006 I had a brand-new K1200S. When it was only 4 weeks old, with only 1,000 miles on the clock, a white van man took me out, and the bike was written off. As I wasn't going to be able to ride a bike for at least a year (due to follow-up operations) it was agreed that I would be paid the full invoice price of the bike, including extras. All this was settled within 4 weeks of me leaving hospital. I would never declare a price less than what I had paid in full for any new vehicle I bought.
After the first year, I trawl round vendors of the particular brand, looking for models of the same age and mileage and use a value slightly above the average of all I find, plus a bit extra for any extras, to declare to the insurers.
