What on earth would you consider normal for a helicopter ride from Exeter to London?
That's roughly 150 miles as the crow flies. Pilot, co-pilot and a medic, minimum crew for say 1.5 hours. Each way, so 300 miles of fuel and aircraft lifetime and three hours of crew cost, not to mention ground crew etc.
My dad got that on the firm when the shit hit the fan and he needed to be seen by specialists in the Royal Brompton and Royal Devon and Exeter decided that was his best shot at life. That was 15 years ago.
Anyway, the OP's bill looked pretty normal until the 11,000 base rate nonsense. How can that possibly be justified?