Speaking for the club I fly with, our owner kept hire prices stable for some 18 months in a rising market before having to 'give in' and raise hire rates.
Given average profit margins in this sector, I think we can hardly accuse schools and clubs of making a killing. Most struggle to keep their heads above water.
Hire rates are also rising in the UK because maintenance costs are rising with the introduction of the new Part M regs - see another thread in this forum...