I'm flying to China on Thursday. I'll be flying Air China for the NRT-PEK-WUH segments. Based on my companies policies, I could get the NRT-PEK segment in Business, but the PEK-WUH segment was originally purchased as coach. I called the AmEx travel folks and when they looked, the ticket was $7 cheaper if the PEK-WUH segment was purchased as 1st class. So now I get Bus/1st for the whole itinerary.

My assumption was that there may have been some discounted 1st seats available and the only Y seats were full price (or something similar.) But I didn't want to pry to closely.