Robinson R22s and R44s have a 2200 hour life from new and have 12 years in which to use those hours.
If the hours are not used, then they are lost. This means that to fully utilise a Robinson from new until the end of its 12 year life,
you must fly 183 hours per year. As a private pilot, you are very unlikely to be flying that frequently.
On the other hand, a flying school will fly considerably more than 183 hours per year, meaning that they will run
out of hours before the 12 years is up. It is this mis-match, that causes most R22s to spend part of their life in a flying school,
accruing many hours in a short time and the other part in private ownership. Some start off at a school and some start in private ownership.
Generally, the more hours that the helicopter has remaining, and the more years it has remaining, the higher the price. Taking account of the number of hours a private owner is likely to use however, you can see that you could be paying for hours that you are simply not going to use.