Originally Posted by EXP100

As noted upgrade offers can change substantially by the minute. For example I had a PHX/MIA flight where the offer for weeks was going for $900+ then suddenly it was down to $272-something I was willing to take. Remember others might be seeing similar or even better offers as this is all dynamic. So if you really want F on a particular flight you should check a couple times a day, each day, and don't blow it off if it's a high amount thinking it won't come down. IME the offer goes away once check in starts at T-24 or of course if every seat is sold. AA will not hold back selling seats for upgrades.