I'm a potter on the side and that operation has grown from a corner of a room to engross a full basement, kiln shed, waking a long time before dawn everyday to work on it, running a small retail shop, etc, so I know how that goes. The good news is that my wife is on board with it. Otherwise it would be bad.
By the way, what prompted the question was that I was asked to consider having a batch of quilts made for resale by someone. When you buy 20d ripstop from OWF the wholesale/bulk price is a couple dollars a yard cheaper than retail. So I was looking to find the same thing for insulation. A couple dollars yard makes a big difference in the retail price when something is marked up. In the final analysis it doesn't seem to be workable financially. Making gear is like being a potter in this respect: you do it because you want to do it and hope to make some money. You'd rarely say "now there is a great business opportunity!" There are, of course, exceptions to that.
Here's to happy marriages!