The insurance company are under contract to provide you with the market value at the point of loss, most insurance will reference Glass Guide & Cap Guide to do this. The best way to give yourself and idea of the market value is to look in the market place for the identical vehicle. Ie same make model year specification and mileage as to the one you have. Take a look here at our pricing to give you an idea: www.honestjohn.co.uk/used-prices/