If you ever find one it will run you anywhere between $500-1000. Possibly more now since none have surfaced in a very long time.
I sadly pulled one of these from a pack (redemption) a month aft Inkworks went out of business. I emailed Mr Razor Leaf himself and asked him if he could help me out. He had recently acquired the rest of Inkworks Autographs, and was only sent 1 MacFarlane Auto, which he said he wouldn't give me because it was his only 1! Needless to say, he only got 1 because there was only 1 that hadn't been redeemed (mine).
I just put the redemption on eBay =(
Heartbreaking considering I opened 50 cases and dreamed of pulling such a card.