I've got it down pretty well. Most of the setup costs are sunk the first go-round. Spare containers, plastic plants, lights, etc. It's the food that costs. And time. Times especially.
I breed my females once a year usually, and only get 15-30 babies per clutch. I learned along the way that it's easy to sell a dozen or so baby lizards during the "profitable" stage in their lives (when they're big enough to sell, but not so big that they hate each other and require individual cages). Any left over quickly become a drain on your space, time and cricket supply.
I know enough that if I wanted to, I coudl breed them in volume and make a lot of money selling them in lots all year round. But that's not fun.
The absolute key is to keep it fun. IF you're having fun, you're doing it right. If you make money, even better.
15-30 babies only costs me a hundred dollars in feeders to raise up - more if it's during hte winter (shipping is more expensive on feeders). Another key - which is kinda tricky - is that I incubate them at lower temps. They take longer, but hatch out bigger. Bigger babies eat 1/8 inch, not pinheads. Most of mine are getting 1/4 inch crickets next week - I only had to order one box of 1/8" crickets for them. A few are still smaller, and will need 1/8" crickets next week though...
the money saved in feeder cost is huge - 1/4" crickets are much hardier and much bigger than 1/8" - but they cost the same.
Last clutch, most were eating 1/4" out of the egg.
And the most important factor in selling them is selective breeding. I paid nearly $100 (plus shipping) for my old breeder, and a lot for his mates. At the time I got him, veileds were going for $15-$20 at the reptile shows in my area. I've only bred 6 male veileds in my life(My original WC male, his son, the big male I had for 8 years and his son, a big blue european male I got a few years back and a WC from Florida) - and I've been breeding them for 15 years. I'm picky abotu the animals I invest my time in.