Skylune wrote:

Capital costs would obviously depend upon the length of the runway,


At remote rural airstrips they tend to be rather short.



number of runways,


Remote rural airstrips tend to have one.



equipment, etc.


Remote rural airstrips tend to have little, if any.



Operating costs would depend on towered vs.
nontowered, number of maintenance personnel, etc. So it would vary.


What remote rural airstrip has a tower?



The point is that very remote areas depend on GA for access, but traffic
volume would likely be insufficient to support the financial operations of
the airport. If important to access to the outside world (AK and some MT
airports), some sort of subsidy would be required.


The point is remote rural airstrips tend to be privately funded.