I was curious whether anyone has any information or success purchasing an upgrade to business class at the airport. I am flying ORD-IST and was told by the Turkish Air operator that it was possible to buy such upgrades, but I was not sure that she completely understood my question. Has anyone done such a purchase, and if so, roughly what was the charge? It is my understanding that neither coach nor business are full on my flight. I'm also star alliance gold if that would make any difference.

Thanks for any insights.

lvnvflyer