See here [1]. It's based on qualified appraisal and/or valuation of similar works at known auctions. [1] https://www.journalofaccountancy.com/issues/2010/jul/

See here [1]. It's based on qualified appraisal and/or valuation of similar works at known auctions. [1] https://www.journalofaccountancy.com/issues/2010/jul/20092096.html https://www.journalofaccountancy.com/issues/2010/jul/2009209...