I am retired from any straight job now, but in the past it was one "day job" after another, some of them lucrative and some of them pitifully underpaid. If it's legal, I've probably done it. I have some retirement income and I make craft items which sell better than my "real" art.
I frequently work smaller than I would like and I compromise a lot on materials. I don't buy impermanent garbage, but I don't use the best paints unless the success of the outcome is totally dependent on them. I also gave up working in cast bronze, a medium I loved, due to the expense. In the past working day jobs meant I never had enough energy or enough time to do all the work I wante