Originally Posted by
daslax
No, although the parameters changed between yesterday and just now when I tried to do it. There is now a Z fare available on my existing flight that is only $40 higher than the fare I paid. I called and asked if I could buy up to F - initially they told me it would be over $800, then I mentioned that if I just went on to united.com I could get the same flight for $400. They were able to confirm this and then told me for that fare I would have to pay the $200 change fee in addition to the fare difference. I politely persisted that on the website I am usually able to buy up with no change fee but there was nothing being offered on the site - she said nothing could be done on her end and offered to transfer me to web support, so I figured why not...
Web support took a lot of time to look into it but had the same result. Buy up offer of ~$800 and only when I mentioned the fare available online were they were able to offer that but no waiver of the change fee. I said no thanks and they offered to check with a supervisor, but came back saying no waiver.
So I'm assuming that "buy up" is limited only to the fares that are the difference between what you paid and the full Y/B/M upgrades. And any of the discounted P/Z fares you have to pay the change fee?
If this weren't a corporate TA ticket I would pursue the refund/repurchase because of the schedule change, but unfortunately I can't do it in this case.

Since this is a corporate TA ticket, why not ask your travel agent to do the buyup, and tell them about the waived changed fee? They have access to a separate desk at United, staffed with (usually) more experienced folks to deal with corporate travel. If you were going to pay the upgrade out of pocket, you can probably ask them to charge the difference on a different card.
or just HUACA.
Good luck!