Writing off the price paid for a car at a charity auction

[pdcolemanjr]

Hello,

I hope a tax expert can answer this. If I were to purchase a car at a charity auction, specifically a car that may be one of a kind without actual fair market value attached to it (as there is no "MSRP"), and it is an auction where ALL of the proceeds go to the charity, and I am writing a check directly to that charity, how much of the "donation" am I able to write off? 

[Bsch4477]

You can’t write anything off since you got something in return for your “donation”.