The upgrade is $150 for that flight (AS upgrades are based on length):

http://www.alaskaair.com/mileageplan/MP_paid.asp

As for the chances - well, I think you know you answered your own question. I've never tried to pay for an upgrade on such a long flight, but I also tend to think that the people who are more regular to AS will tell you that the odds are going to be low.

Mike