&gt; So each transaction costs 11000&#x2F;2000=5.5 USD<p>No, each transaction costs <i>at most</i> $5.50 USD. You haven&#x27;t established any lower bound in your calculations. A better approach would be to calculate the average number of hashes required to mine a block and the power efficiency of the latest generation ASIC miners.<p>Also, for what it&#x27;s worth, $5 is much cheaper than a Western Union or SWIFT wire transfer so even this upper bound doesn&#x27;t mean Bitcoin is uneconomical compared to modern banking.