Originally Posted by
Eujeanie
When you check "Mileage Upgrade", you get a double column of higher fares, either refundable or not. I assume those are the fares you would have to pay to use miles to upgrade?
BUT...the U is gray and x'ed out, meaning no upgrades on that flight at this time, right? So why would I choose to pay a higher price? In the hopes of maybe upgrade space opening up? And what if it doesn't? (this is on a popular EWR route).
You have it basically correct.
To get an instant upgrade in advance (using miles, gold guest upgrades, by status, etc) you need three things:
1. The cost for the upgrade you're doing (ie enough miles)
2. A fare class high enough for the type of upgrade you're using
3. Availability in the upgrade fare bucket ('U space')
In your case, you have (or would have) #1 and #2 but currently are lacking #3. So as you said, there isn't a benefit in paying more now unless Alaska adds more U space to the flight you're on.