It seems like a lots of money, who is going pay for it? (taxpayers? banks? you tax bad language? you print money? ...)
Libertarian hydra still approves it - as a replacement of the current overly complicated social system.
To quote myself from the OP: "the unemployment subsidies + underlying bureaucracy in Germany can be redistributed among the 80 million Germans at the rate of about 12.5k EUR per year. So 1000k EUR of basic income guarantee per month is realistic. This can be further expanded with several different approaches to taxation." I have to declare that I lifted this quote from a politician's mouth, so its veracity is not certain. But I'm sure there's at least a grain of truth in it.
Other ideas are to have a larger income tax, or a larger VAT tax.