Actually a large portion of the anesthetists fee goes on professional liability insurance in case he accidentally kills you.
Plus of course before one can specialise to become an anesthetist I am pretty sure one has to have qualified as a doctor.
I, for one, think the anesthetist who attended me on my visit to CXH in January did a superb job and I was very happy to pay his fee. I think they must charge by the hour because for a revision mine was a bit less, and well worth it!
I think if you go to an NHS hospital the fees for your stay will be pretty eye watering, which is why most SRS gets done in various smaller private clinics like the one in Hove.
The colon op is unfortunately much more complex and hence an order of magnitude more expensive.