It is impossible to predict. However, let's generalize. My bet is the following:
if you wrote a hub a day for six months (180 hubs) and did the following:
a) Observed SEO principles
b) Wrote unique, length, flag-ship style hubs
c) Did a minimum of marketing
Then you could well be making several hundred dollars a month by the end of it. The end of the year would see you getting close to low-grade financial self-sufficiency.
The more you put it, the more you'll get out.