You might have overlooked something when pricing your Brimstone, Blizzard takes 15% right off the top for sales.  So $90.30 * .85 comes out to $76.75.  And the price of Bitcoin is greater than $7.675/BTC right now.  And that's only if you're cashing out to Blizzard bucks, if you wanted to cash out to Paypal there's another 15% fee bringing you down to $65.24.