In addition to the Gross Clinic, some of Eakins most well-known paintings include Mending the Net (Philadelphia Museum of Art) and Max Schmitt in a Single Scull (The Metropolitan Museum of Art).
The only true test would be to see if any of the items valued were transacted within 24-36 months of the valuation (basically two to three cycles of the art market) and then compare the actual net auction proceeds to the heirs to the valuation by the Panel.
To estimate billionaires' net worths we value individuals' assets, including stakes in public and private companies, real estate, yachts, art and cash--and account for debt.