So I am guessing that I could not buy that fare, and then move the dates to the ones that I want (12/5 out and 12/14 return, with some flexibility) where there are P class fares, but I cannot make the advance purchase requirement.

Maybe I can buy that fare, attempt the move with-in 24 hours. If the move cannot be done (or cannot be done without adding $4K to the ticket price) cancel the original ticket. Never mind - too convoluted, and with SHARES I can assume something would go wrong and I would be out $2500.

I'm going to figure out the cheapest miles+co-pay combo.

Thanks everyone.