Did he calculate the tax based on the full face value of your purchase, or the discounted amount you paid for it?

FORBES: Social Confusion: How Do Sales Taxes Apply To A Groupon?

Each unit of Terra currency would be charged each year a transaction fee of 3.5% to 4%, assessed against the face value of the currency, depreciating its backing by that amount.

FORBES: Rethinking Money: The Rise Of Hayek's Private Competing Currencies

This will clearly and obviously lower that e2 value, the amount of avoidance that anyone can do in the face of higher tax rates.

FORBES: Why France's 75% Income Tax Rate Is Going To Be So Disastrous

In theory this policy of buying and cancelling some of the debt would reduce Greece's indebtedness, because the market price of its bonds is a fraction of the amount originally borrowed: if the EFSF paid 50m euros for Greek bonds with a face value of 100m euros, and agreed that Greece should have an obligation to replay only the 50m euros, that would reduce Greece's indebtedness by 50m euros.

BBC: Practical steps to prevent eurozone meltdown