Some good answers here - I, too, find myself somewhere in between. I do make some money as a writer, but not nearly enough to yet consider it my profession - my hope is that will soon change. The truth is, it's taken me a while to get to the point where I truly believe I could make a living as a writer; I'm the oldest of five kids, and the only one that didn't do business for my undergrad (and my father is a chartered accountant). The idea that I could write for a living just seemed more like fantasy - it was what I was passionate about, but I just saw it more as an escape than a reality.
It is what I love to do, however, so I'm finally just giving it a shot.
Of course, I completely understand this perception that by trying to make money out of your writing, you are - to a degree - 'selling out,' but the truth is we all need to eat. And if I can make a living out of doing what I truly love to do, then I'm among a very fortunate and blessed minority.