Soop, first I have no problems with private medicine, having worked as a nurse in a major private hospital for many years.
I'm wondering how you chose this surgeon. In all my years I've never come across an eminent surgeon who is 100% private unless of course, as is often the case, they are newly-retired from the NHS.
Surgeons gain their experience, prestige and reputation by virtue of their links to the NHS, the university, research, published papers, etc.
I'm not casting aspersions on your chosen surgeon as I don't know who he is, but would urge caution before you spend £25,000, an enormous sum.