There's another thread on business going around here about the difference between a job and a business. Maybe worth looking at. Also, the first thing that came to mind when reading the opening post, is why you would limit yourself to such a small income...?
James, great start, and great approach of doing business (no matter small or bigger), BayView has the similar mindset do business as you, which definitely would be the way I need apply and practice in the future.
And you asked a good question as well, although I don't want to limit it to that income, it's all because my wife gets pregnant, her full-time job's income is about that figure, that's why I hope I could cover that part and let wife focus on our baby!
Thanks!