yes, i think that is the reasoning, that the donor already took the deduction...i think the charity is supposed to let you know how much of the item is an allowable deduction (or rather is not deductible)...
>>Is that the reasoning behind the tax code in this case - because Joni is already taking a deduction for part of it (a value I suppose she would determine absent a formal appraisal) the buyer can only take a deduction for the balance over and above what Joni takes?<<