The answer is that if you believe that an insurer is not paying you the full value of your claim or your property, you can sue them to try to force them to pay more. Like any or all lawsuits, success, however, is not a given--you will have to prove in court (if they don't settle earlier) that the actual value as of the date the motorcycle was declared a loss was $1,800+ (note: you can't recover for fees and taxes--only for the actual value of the bike itself). It may or may not be worth doing this: for example, you'd likely have to handle the lawsuit yourself, inasumch as hiring a lawyer to try to get an extra $1,000 or so is likely a break even proposition at best, and very possibly would represent a net loss to you.