There is also the motivations of the scanner owner to consider. They are paid to do scans. A cheap scan might be low hundreds of dollars per hour. A more commercial rate would be well into the thousands. We don't want to dry up now do we?
The scanner owners are almost all universities. One typically does have to pay to use the scanner(and quite a bit--$500+ per hour is typical), but this is typically meant to cover the scanner costs. The equipment costs at least four million dollars, plus some ongoing costs (cryogens, typically a full-time tech or two, and maintenance; the power bill is probably not trivial either).
