I don't know... I guess it depends on a lot of factors. What era, what kind of musicians etc. etc.
My guess though, is that musicians generally are people that are not under the radar. You might be a pretty simple person living in a one bedroom apartment downtown, or even sharing an apartment with a roommate, and you play a few gigs around town, in some bars etc. and then you happened to know someone, or play in a band, and then you get this gig playing for the President, or any other super high profile gig, and you get treated like a King, you get to stay in very cool hotel, the hotel is super busy, they run out of rooms so they have to give you this incredible suite that cost $1200 a night, and you get paid a lot of money, etc. etc. and then the next day you are playing at the local bar in your home town for $50 on a monday or tuesday night! LOL
I think unless you are really famous, most musicians on an average basis to they share of low profile gigs and high profile gigs, maybe one more than the other, and/or somewhere in between. And as far as the life style, i think that amongst the guys that are professional musicians but yet unknown, that can be all over the place. Some people might be considerably more successful than others financially and yet be completely obscure to most people. And I have a feeling that it's been like that forever. Sometimes, we get to hang out with some real wealthy people, very intellectual people, famous people, but also with the average Joe, drunks, and everything in between, you name it. I don't think we can be put in any category. All kinds of people, from all kinds of walk in life take a look at us, and they go like: "Yeah, this guys is OK! ;-)