If per-person, population of the US is currently about 330 million. Doing the math, that's $3.3 Trillion per year in payments to be made. Social Security expenditures in 2008 were about $615 billion. There are obviously other programs that people qualify for, and I'm specifically excluding Medicare/Medicaid because they're health programs, not living-expense programs.

Even so, if the income guarantee program were implemented, expenditures in this arena would go up by about a factor of 4 to 5.