I'm about 4 months into my business. We paid off all of the debt, my hubby still has his job/insurance that covers us both. I semi-retired, with a small eBay business to fund my quilting business. I thought about the craft show circuit, but so many people pass your booth saying "I could make that myself so much cheaper!" So I learned how to make the patterns! Now when I hear that, I know I'll make a sale!
I have only 2 patterns in print right now, so I haven't done those expensive booths yet. I'd like to have 4-6 in hand before spending $1000 on a booth! Only selling now online and through a few pattern sites as well. It hasn't taken off yet, but I have faith in my project.
I started my eBay business about a year before I quit my regular job so I'd know the time and money involved. (I buy stuff at auctions and estate sales and re-sell it. ) I learned to buy only stuff I know I can flip fast and for at least double the money. It has to fit in my car and be easy to pack and ship. It's been fun to learn and both businesses have been a great way to write off all of my quilting supplies, fabric and a few other purchases-not to mention the mileage deduction.
Don't kid yourself about time. Everything has a learning curve. My drawing program, any photo program, putting up a website, learning Instagram, twitter, Facebook, pinterest, blogging, different online outlets for your products. It takes time to learn them and get them to be second nature so you're spending more time on your business than your technology.
So- start small. If you love what you're doing, it won't wear you out after your day job. You'll learn lessons (make mistakes) specific to what you're doing while you still have an income and it won't be fatal to your bottom line. You'll see if you like it enough to do it full time. You'll learn how to price your services where you'll get customers and feel good about what you're making. And master one technology thing every month or so. Let your hobby help pay off your debt before you leave your job.
I think you'll be surprised how much less you dislike your job when you have an exit plan in the works!
Good luck! It's a journey!