Originally Posted by WineCountryUA

Long hual international are not eligible for the YBM instant upgrades (only flights that also offer complimentary premier upgrades are eligible for YBM upgrades.) See Upgrades overview.
However mileage + copay (none on B fares) is an option -- would take 35K miles and you would be at the bottom of the priority waitlist.
Or you might be offered a cash only upgrade opportunity. If offered (check online and at check-in) likely to be roughly $800 to $1K+ http://www.flyertalk.com/forum/unite...-upgrades.html