[cortic]

>an average worker would have to pay for two UBIs in taxes

An average worker would be paying less tax (in real terms) if we moved to UBI than they are paying for the current system.

Its also true that this isn't just going to be payed for in income tax. VAT and corporate tax will contribute as well, meaning people on UBI will be paying for it in part as they spend it(VAT), and as they don't claim some of their other allowances in benefits, healthcare and law enforcement we will save even more.

Try to stop thinking about this as 'the average worker' the country is a good deal more complex than that. systems will pay for themselves in a host of ways if they are needed and efficient; UBI is a more efficient income support system than the one we have.