ATMs are plentiful and while you might lose a few % if your card has foreign transaction fees, they are an easy way to tailor your money needs. You probably don't want to be stuck with excess RMB, so don't worry if you don't take out enough to start.

As for maglev prices... I wouldn't take the maglev from the airport... the taxi at Longyang Road (maglev terminus) can be intimidating and demand outrageous prices.. If you want the maglev take it in reverse, back out to the airport.

You'll need about RMB60 per taxi to get to the terminus, then RMB40 per passenger for the maglev itself. You may need two taxis depending on how much luggage you have. Hotel staff will get you in the taxi and on your way to the maglev.