But that your government recognizes bitcoin as a currency? I doubt it. Your income in bitcoins according to the law is not revenue. If you buy goods with bitcoin it does not fall under the tax base. If you exchange them for your currency, then taxes will have to pay.
But we still pay a sales tax on the item. An item is bought, is recorded as being bought through the tax money it generates, yet is allowed to be bought by something that is not recognized as legal currency.
It's a loophole that shows that regulatory bodies care more about their money than ours.