[glchen]

I would refund the cost of the ball + the shipping cost to the buyer, but nothing more than that (and none of the shipping costs to the TPG). I would probably advise potential buyers if they are unsure of the auto, they can go to PSA for a quick opinion that is just a fraction of the cost of the cert, so that they can obtain some initial assurance that the auto is genuine.

BTW, when I was selling photos on ebay that I was pretty sure were Type I (because they had the newspaper clippings and date stamps on back), here is what I put in my listing. You might want to do something similar:

"Although I am nothing close to a photo expert, I guarantee that the photo would be a Type I, and if you send it to PSA/DNA for verification within 45 days, I will offer a full return policy if it does not come back as Type I. (However, I will not refund grading fees.)"