I know one FI who was salaried at 45K, before he went to a big charter company, he was flying on the companies AOC also.
Another who is on about 45K per year now, also on the AOC (different company)..
It is not the norm, but does happen particularly when the job involves being Head of Training or being an examiner.
There was a now defunct company who pretty much had a standard 25K FI(R), 35K FI. 40-45K CFI/HOT. All involved being on the AOC if holding a CPL.
In the summer some experienced FIs have been known to command £60 per hour plus, seem to remember one being a PPL(H) with grandfather rights who obviously was not doing AOC work.
Rotorvation I think you are right about the Onshore IFR Twin market ( I am biased however). I know of several people earning 80K + benefits in Ireland. 70K++ is becoming the norm in the UK, some with week on / week off in the UK corporate market.
GS