Only speaking from my own experience here.
There's no real etiquette to it, I just go with the flow. If the session gets off to a passionate start, then the massage just naturally takes a backseat. I'm talking about sessions that start with a great intimate hug, my hands going on auto-roaming, then lots of kissing. The sex follows without any talk of $$. And it does happen even with girls I was seeing the first time.
If the sesh doesn't start this way, I'd never suggest going with sex first unless I regularly saw her. I'd just go with what she's happy to do first.