Those answers are going to depend a large part on what types of animals you plan on breeding. All of them will be a little different as far as start up and maintenance are concerned. Some things to keep in mind that will remain consistent though:
Startup costs: racks/aquariums, heat tape, lamps, bedding, the animals themselves
Maintenance costs: more bedding, food, electricity, vet expenses
If you're "economical" you can consider some of those costs reduced or non-existent. For example, a lot of people use newspaper as bedding for ball pythons which costs them nothing. We breed our own rats which cuts down food costs substantially. You can also build your own racks/enclosures and pay 1/10 the cost of a premade one, but then you have to consider what your own labor is worth. There are a lot of factors that play in, so you might just have to do some research.
Another thing to take into account with animals is that there's no guarantee on product. In a factory setting, you buy the materials, pay workers to put them together, and get your product as expected. With animals, they may or may not breed, they may or may not have fertile eggs, the eggs may or may not make it...there are a lot of unknowns when you consider breeding.
Also, if you're taking morphs into consideration, you can statistically figure out what you expect to get but you might have a bad year. You could expect a bunch of $500 designer animals and get nothing but $20 normals, it's completely random. Obviously you can 'rig' the stats to some extent depending on the animals you start with, but you get the idea.
I guess what I'm trying to say is that it's hard to set anything in stone when breeding animals. It's definitely not like any other business I've had.
I do this just for fun.