High but not outragous these days, worth considering an atternative quote if you can.
The last thing that insurers want is cars to dispose of so you won't have to buy it back. When a similar thing happened to my wife's car a few years ago, I was expecting a row when the guy turned up for the inspection. He had it all on his laptop, parts specs and costs, values etc. Agreed it was CTL and made a provisional offer there and then.
One thing to be aware of if they agree a write off. There are have to declare it to the DVLA and its logged against the car. It sounds like yours would be the lowest category of commercial write off but you still have to take the repaired car off to have it inspected and the DVLA computer updated. All they do is check the numbers and paperwork so its a bit pointless. Another minor inconvenience.
GTV and Racing Driver