At the end of the day, rental grazing is only worth what someone is willing to pay!
You also must look at the economics. If I've got a paddock available for rent on a short term grazing agreement, the chances are I'll not achieve the same income by having x number of sheep per acre as I would if renting to a horse owner.
On the other hand, sheep are less likely to damage the land therefore at the end of the rental period there is less likelihood of expensive maintenance being necessary. Fencing generally needs to be more escape proof for sheep, and while the agreement can contain clauses regarding maintenance and repair, there needs to be reasonable fencing in place to start with.
To benefit the land generally, we'll also cross-graze alternating with sheep, horses, and cattle, all on short term grazing agreements, followed by a rest period.
Prices will vary accordingly, but I guarantee there will be more people seeking rentals than there are rentals available!.