I've become pretty used to the Delta set-up where after booking you are presented with paid upgrade options to Comfort Plus or First Class.

However Alaska only seems to offer Premium Class paid upgrades after ticketing, but not any option to pay the difference in fare for First Class.

I have a situation where the Main Cabin, N fare that I purchased is now only $35 lower than the First Class fare for my route/journey. Buying up would be a no brainer, but there seems to be no possibility to do that.

Has anyone had any luck doing this with Reservations? The challenge is that this is the return leg of a roundtrip, so if I cancel and rebook, it will thus also wipe out the outbound journey which I want to keep.

I also often have to purchase Economy Class only per the client, but then use a personal card to upgrade and cover any upgrade cost at my own expense, and it's great that DL makes this easy, but so far can't figure out how to do this with AS.