There is a good chance the schools own or lease back the R22's and so don't really pay for the capital cost.
The G2 is expensive to buy and so if they are mortgaged, lets say 80% LTV, on a (350K EURO) $420K machine then the repayments on a mortgage are $47K per year based on 5% over 10 years. If the machine flies 250hr/year then that's $188/hr in additional cost over the R22.
Purchase price is an important parameter, even for hard working machines.
I personally think the G2 is not terribly attractive as a private owner machine, as its too slow and can't carry enough. Therefore, there will be very few wealthy owners buying them for personal use and then leasing back to schools to offset fixed costs.