The new Mac Pro is the most powerful and flexible computer Apple has ever created, and it’s also extremely expensive — or is it? With a price tag that can climb up around $10,000, Apple’s latest enterprise workhorse clearly isn’t cheap. For businesses with a need for all that muscle, however, is that steep price justifiable or is there a premium “Apple tax” that companies will have to pay? Shortly after the new Mac Pro was finally made available for purchase last week, one PC enthusiast set out to answer that question and in order to do so, he asked another one: How much would it cost to build a comparable Windows 8 machine? Futurelooks editor Stephen Fung started out by