I want to make a charitable donation in bitcoin.  However, it seems that I need to get a third-party appraisal from a qualified appraiser for the bitcoin value in order for the donation to be tax-deductible.  The cheapest one I can find costs $600.  This seems quite expensive considering bitcoin isn't hard to appraise (a few minutes on the internet would do).  Does anyone know of a cheaper alternative?

Thank you very much.