How much does one orbit of observing time on the hubble space telescope cost?

Observing time on the Hubble is not for sale, and you can't buy it. It's allocated by
the committee responsible for the use of that resource, to the researchers who
submit the proposals that the committee decides will result in the best contributions
to the fields of Astronomy, Physics, Cosmology, etc.

By the way . . . roughly 1/2 of every Hubble orbit would be of no use to you,
since the instrument is in direct sun, and must be tightly sealed and protected
during that time.
Observing time on the Hubble is not for sale, and you can't buy it. It's allocated by
the committee responsible for the use of that resource, to the researchers who
submit the proposals that the committee decides will result in the best contributions
to the fields of Astronomy, Physics, Cosmology, etc.

By the way . . . roughly 1/2 of every Hubble orbit would be of no use to you,
since the instrument is in direct sun, and must be tightly sealed and protected
during that time.