£1500.00, that about what the motors worth I'd have thought! It's a simple job to drop the box, and to see if the problem is shaft or not. It's pretty easy to remove the powerhead as well, no special tools required.
In the old Honda 130 class racing days, we used to remove and replace a powerhead in a morning!
Out of interest, who's the engineer that's quoted that ridiculous price. Around here that equates to around 25 hours at a main dealers. You can build a complete motor in less time than that!
It is better to remain silent and be thought a fool, than to speak and remove all doubt!