Travel nurses usually get paid a lot more than staff RNs. I know when we changed computer systems the travelers got paid even more than usual … I'm talking twice what the rest of us made plus housing stipends and some of them get bonuses either to sign on or extend their contract.
San Francisco Bay Area and its outlying regions pay very, very well.
Cost of living can be high.
There's a salary-survey thread floating around, by TheCommuter as I recall, in which I posted relative cost-of-living data for comparison with the anecdotal responses therein.
I'd focus more on where you want to live and don't want to live and then start looking at compensation.
I work with a number of nurses from various parts of the country including NYC, Chicago, Seattle, San Diego, and Detroit and they all feel like they are doing much better here than from where they came.