Steve's barking; The cost of single payer healthcare .

Now I keep hearing that the cost of single payer ( or as I want single payer ( the government gives you a voucher from your taxes to buy health insurance) would cost trillions of trillions of dollars.
Because I don't have the figures in front of me but I know how to figure it out..
First we get the figures what the states and local governments pay toward health care, as in the case of states is 20 to 30 percent of the budget. I don't know what local governments pay but I imagine it's about the same. Then we take what businesses pay, add that in. Next we take what all employees pay and add that in. Next we add in what is payed by Americans who buy their own insurance.
If we decide to eliminate co pay all together we add that in. Maybe if we want to put eye examines and glasses in to the mix along with dental we find out how much the cost of insurance is being payed plus what those who don't have insurance are paying. That's shouldn't be a tall order for all those think tanks.
Now we go to the negatives or how we're going to pay. Number one states will no longer be paying health cost there by eliminating a percentage of deductible ( even standard deductible) that the tax payer pays. Medicare payments as we now know it would be eliminated. A health tax will take it place. Heath care accounts will no longer be needed. Deductions will be reduced, health care decision  not needed. Now we get into tax the rich for the rest of health care. No not really, There are many imaginative ways of taxing(?) such as a having a health tax for corporations that move headquarters to avoid paying corporate taxes. A one percent health tax on any corporation foreign or domestic that does business in the US of A.

The reason I'm writing this is nobody has explained were they got their trillions and trillions added to the public budget.
We just have to believe economist on faith, while they don't explain how they got their figures from.