I got an e-mail from US Airways about the option to upgrade to First for $249 on an upcoming flight JFK-PHX. The e-mail said if there were open F seats 2 days before the flight, I would be upgraded and my CC charged automatically. More info on that here:
http://www.usairways.com/en-US/FAQs/...irst_000000000
I also understand that US Airways gives the option to upgrade at OLCI 24 hours out ("GoUpgrades"), if seats are available. Obviously you have a greater chance of a paid upgrade clearing 2 days out rather than 1 day out, but what is the difference in price between these two options generally?