Still, even if a state does buy land from the feds, would they simply absorb those areas into their own state park systems - and thus add large new budget items to their own budgets? No, that doesn't have to be the case.
Private companies already operate the commercial activities - lodges, shops, restaurants and the like - in treasured national parks, including the Grand Canyon, Yosemite and Yellowstone. Similarly, the Forest Service makes extensive use of concessionaires to operate and maintain complete parks and campgrounds better and cheaper than government could.
States could use this model to take over parks - without absorbing them into the state budget. One Forest Service contractor in Arizona recently offered to take over six state parks that were going to be closed owing to budget cuts. The company would collect the same visitor fees the state charges today while taking the operations and maintenance costs off the state's books entirely. Not only that, but the company would also pay the state an annual "rent" based on a percentage of the fees collected, turning parks into a state revenue generator instead of a loss leader. The state would still own the land, and the company would be subject to strict state controls on operating rules, fee-setting and development restrictions.