Well, I have never seen flights this cheap between Phoenix and California, ever. So that is a good sign of things to come! Right now you can book a one-way to San Francisco from Phoenix for $29. That is like 6 drinks from Starbucks. There are also a few flights between Phoenix and Denver for $29 as well. (these flights between PHX and DEN are normally pretty cheap so I am not as surprised, but a great deal nonetheless!)
These $29 flights are on Frontier Airlines, not my favorite airline but they will get you there in one piece! They charge for everything including putting bags in the overhead bin above your seat so keep that in mind. You can bring a backpack and put it under your seat for no charge. Use google flights to find the best dates and prices, they have a graph that shows which dates are the cheapest.
There are also some good flight deals involving Vegas. You can fly San Francisco to Vegas for only $44 one way. There are flight deals on either United Airlines or Virgin America for the same price. I would definitely recommend Virgin America. They have better on-time reliability and such a cool in flight experience
If that mood lighting on Virgin America doesn’t get you ready for Vegas I don’t know what will.