If it turns out that you end up losing money over time, will you still continue to do it? Sounds like you have very little overhead, which is a boon, but when you consider how much your time is actually worth it doesn't seem possible to even break even on a 10 gallon system. OTOH if you are doing it to prove a concept and get someone on board who wants to fund a real brewery then it could be totally worth it. Just my .02. Not trying to discourage anyone from their passions.
As I've always said, I like to hear everyone's point of view. I live in a town of about 30,000. the next bigger town is about 75 miles away. I'm not in this to really make a money. But, I will say that my business (that is working out so far) shows that my partner and I will net, about $120 for a full day in the brewery? The math works out to be about $6/hr. I know of know other hobby that I love so much that will aactually pay me $6 to do. Can I quite my day job? NOT EVEN CLOSE. And it may be that after a couple years of this, we decide it's not worth it. But I can tell you that a day in the brewery with the woman I love, making darn good beer, is a very enjoyable activity. We met because of homebrew two years ago. And, we're getting married on the 18th.
But, I know our model does not work for most folks when they think about "going pro." I post my story and experience to show it is actually quite simple to go legit, and sell one's beer.