An explicit floor for the valuation, rather.
For a stupid example, say someone makes electricity stop working. But there's lots of things that could make it less valuable in the future than the value implied by the recent sale.
People regularly spend millions on sculptures which are indeed just special rocks. The Guennol Lioness comes to mind.
Then, if you made the rock cost a negligible amount of money given the regular payouts on such ventures, I would really start considering it. Don't be a boob.