It sounds like you’re doing research, but I do want to warn you there’s a lot between not breeding and “if it doesn’t work out.”
There are babies that have to be hand fed every 2 hours around the clock. There are times when the hen becomes egg bound, especially if she’s not getting extra calcium. If you don’t get vet intervention, she can die.
There are times when all the babies become ill; vet costs will eat you alive.
And there’s the expenses of buying more cages and more food, should the babies make it.
I’m not trying to scare you but this is reality and you need to go into it fully aware. I breed finches and have encountered all this plus more. We never get out of the vet for less than $200 and usually it’s twice that.
Another thing to think about. Are there already cockatiels in rescue where you live? If so, there is an over abundance already. This is why I don’t breed my tiels. Where we are, there’s always a handful at the rescue. So if I were to breed mine, I would be contributing to the problem and maybe knocking some of those (the rescues) out of a chance to have a home.
Just some food for thought