The cost of the land + the cost of utilities + the cost of property taxes + the cost of maintenance + the cost to improve the property to make it camper accessible + the cost of business licenses + the costs of any permits

A pack in pack out campground with no facilities, utilities, parking pads, grills, or doodads will be far less expensive than one with these amenities.

For a pack-in pack-out, you sell the passes online. You walk through once at noon to make sure everyone that is supposed to be gone is gone and then again at closing (9pm? 11pm?) to make sure everyone has their pass posted.