Where did you get the figure of $30k/person from? My understanding of basic income is that you'd get only a very, well, basic level of income from it somewhat equivalent to basic unemployment benefits now. In the UK you get something like £65 JSA + £70 Housing Benefit a week which works out something like $10k/year. That's $3 trillion according to your figures[1], or a total budget of $5 trillion. That's a substantial increase to be sure and would be a massive social change but rather more feasible to fund.

[1] In reality you presumably don't pay a full amount to minors.