Well, all I know is all the SE UK schools pay around £50 per flight hour and there are a lot of instructors who do it as a "hobby job". either they have other "non-flying" jobs (IT/property etc) or they work offshore in flying/airline jobs etc
While instructors are happy with £50 per hour, schools have no incentive to pay more
There is nowhere that will pay £400-£700 per day for an R22 FI