TCurrency cost is up to the provider. Licensed TCurrency providers will be able to sell you TCurrency for the face value of the TCurrency plus up to 15%. Example: You purchase $50 in TCurrency from a licensed merchant whose rate is 4%. Hence, your cost for $50 in TCurrency would be $52.00 ($50 face value + $2—which is 4% of $50).
See how to purchase TCurrency here: