Grossly excessive fees?

There was a fascinating story in yesterday's Times  and Mail online on a leading surgeon being referred to the General Medical Council for charging "grossly excessive fees". £12m was charged to a member of the Brunei royal family for breast cancer treatment.

If the report is correct, it begs a number of questions:

1. Do the GMC have policies on fees?
2. What constitutes "grossly excessive"?
3. Is there a difference between "grossly excessive" and "excessive" fees?
4. What constitutes fair and reasonable fees?
5. Would the view be different depending on whether or not the treatment was effective?
6. Does the relative value to the recipient have a bearing on the view?
7. Did the recipient have the option of an alternative provider?
8. Is there ever a situation where the surgeon is paid by results?
9. What's the GMC's view on fees charged to private patients in the UK by comparison to those a surgeon is paid by the NHS for like-for-like treatments?
10. Should the principle of accountability and unacceptability of charging "grossly excessive" fees be applied to other professions?