When looking to upgrade, and speaking to one of the CO agents, be sure to ask for the 'lowest possible' upgradeable fare. They will then usually check both HoKeY fares as well as the fee 'enhanceable' lower fares. On a recent inquiry regarding EWR-LGW I was quoted a H fare of $1278 or a T fare of $316 + $400 x 2 for the upgrade = 1116. Yes, she did book me on the latter, and advised that when my upgrade comes through (I'm Platinum, so she figured it was pretty certain plus I'm travelling in mid Nov) I'll be charged the additional $800. The miles though, (40,000 r/t) get taken out immediately from your OP account.