Like anything else, the NFT is worth whatever price you can find someone willing to pay for it. Unlike virtually every other asset, the NFT has no other use: it represents ownership for the sake of ownership. Since it's non-fungible, there is no (apparent) substitute that would be equally "useful" to own, so the NFT has value as long as someone else is willing to pay to acquire ownership.
I think the closest precedent are the Rai stones used in the Yap islands for currency. You don't need physical possession of the stone; you only need all relevant parties to acknowledge that you own the stone, regardless of its location.