Shouldn’t I use the dealer or auction house who sold the item to me?

Appraisals for an IRS-related use cannot be prepared by the merchant who sold the property. These merchants may not possess the objectivity to allow them to arrive at an unbiased conclusion of value. For example, a dealer may increase the price you paid for a work to reassure the buyer s/he got a deal to use that as the value. Impartiality and competence in valuation define appraisers.