depends what kind of UBI we are considering. if you get $10k each for you, your wife (assuming you are married), and each child, you might be somewhere close to breaking even after taxes and the expenses you mentioned. if only you and your wife get the $10k, you're looking at a pretty tight budget.

imo, only the latter setup is reasonable. I'm all for giving individuals the freedom to float around for a while figuring out what the want to do, or even subsist for their whole lives if they don't "click" with any work that's valuable to the market. but I don't think it's fair to make the taxpayers support however many children you decide to have.