The "real" cost is what YOU pay for it.
The variables are:-
Insurance (so flying owner only is less than Club or As Required). So if you want to hire you need at least Club insurance, but can recover some costs.
Fuel per hour (known index per aircraft)
Based aircraft charges (landing/ hangar/ nav charges applicable to base)
Oil (.5 qt per hr)
Maintenance (50/ 100 hr charges for the R22) - this varies WIDELY in the UK (the range based on my review of the market in 2004 was 100% variation between lowest and highest, so this is a factor for owners)
Unscheduled maintenance (outside of the RHC std cost card) - my worst in one year was £60,000 due to unreported damage by a flying school, so this has quite a big impact on the individual cost card even over a five year plan.
Your margin - either you get what you ask for it at the location you want it to be or you do not. (see demand and supply below).
As you have done, divide by planned hours to establish annual charge.
There are two hard economic realities in play:-
1. Demand and supply, and there is no real shortage of R22 type machines for training leaseback. At certain times (a few months at a time), or in certain geographies, demand exceeds supply. However this tends to be short run.
2. Slim margins in aviation. Thus schools aim to pay as little as possible in order to make money from the use. Many/ certain schools own NO helicopters and just lease in machines from private owners. Why? No maintenance or unscheduled maintenance costs (the big item above). If there is damage then as long as they are flying a lot of hours then the increase in the owners maintenance passed on to them in a hourly usage charge is quite small compared with the saving in capital used on repairs. They only pay for what they use and thus can often have working capital in the bank before the bill lands.
As a flying school, why would you WANT to own machines ???
The least cost/ lowest risk/ best return is to have a few SFH pilots who fly a lot of hours and do so at low risk. The problem is finding them in a given geography if there has been a shortage of training in that region to generate high hours safe pilots .....
Ah, the eternal serpent..