Originally Posted by
1KHI
GG BUYUP (for continental) - Did you buy a low fare class ticket? Want to buy up to a higher fare class to ensure an upgrade (e.g. Y/B/M or even a true F fare)? Call in to the reservations line and feed them this little ditty and you'll be on your way without having to pay the change fee on your ticket; you'll only pay the fare difference. Sitting in first class has never been easier.
Its possible, but what you will be spending in the fare difference will *probably* be far more then what the co-pay on a upgrade with miles would cost.
Now, as far as on the day of departure it could be significantly cheaper (provided you are even offered a buyup).