I underwrite and sell motor trade insurance for one of the largest uk insurers.

They will assume being in the trade you will have access to trade price cars hence why the offer will be made on that basis,If however you can prove you paid market price for the car or your business is not buying/selling cars (ie bodyshop/servicing) they may increase offer if you ask them.

I assume you have SDP use for your wife to drive?

how much is your xs? How many years ncd do you have? Most insurers give up to 45% on 4 years or over and normally steps back to 20% ish on 1st claim which will increase your renewal

For the value id advise against a claim