Originally Posted by
mahasamatman
When the price may be twice as much?
The price won't be twice as much, though. As
findark pointed out, the prices for W/V fares rarely move much, if at all, and unless you're traveling during a peak period, it's likely that you'll have W availability much closer in.
The best approach, by far, is to monitor for PZ availability and book if/when it occurs; that keeps you from having to guess where it will open. PHX-NRT can be sanely routed via LAX, SFO, and DEN; buying a ticket now locks you into one of the three, essentially cutting your upgrade chances by two-thirds.
For W/V fares, I wouldn't start to worry about missing the boat on price until a minimum of 6 weeks prior to departure.
Note: OP -- to look for PZ space, make sure you're searching LAX-NRT, SFO-NRT, DEN-NRT, etc. Don't just look at PHX-NRT. It's a lot more common to find upgrade space in advance on long-haul flights than short-haul domestic flights. If you search PHX-NRT, you only see PZ > 0 if it's available all the way through. I'm guessing you'd be willing to manage PHX-LAX in coach if it meant you could upgrade LAX-NRT immediately, though.
