If you buy into quality, you can produce quality and get a faster ROI, but if you buy into "pet" quality, you will get a lot slower ROI. The Market is good in some areas, but harsh in others. If you want to break even, you're not asking too much and should be able to break even each year with your clutches from 3-5 females, after considering the amount of food it takes to get them to size, heating them, and providing caging / substrate, etc.
Don't breed into the market though, always breed into your passion. Get animals you're excited about, and then use that passion to create amazing morph mixes that you enjoy. It's MUCH easier to sell a snake you think is the most amazing thing in the world, than trying to offer a "low quality pastel" for a bargin of a price . . .
But yes, the first 1-3 years is all about investing, after the 3rd year, you should be able to start breaking even and if you're lucky with the odds of genetics, start seeing a positive return on investment.