In the case of the mac pro we are talking about a beast of a machine when you get to the top end. This is the specs of the most crazy one you can buy off their site:
IIRC you can actually order an even higher spec’d one if required for very high-end uses. Anyway, a 12 core Processor and 2x6gb video cards do not come cheaply, unless you’re apple and can demand better pricing because they’re the only manufacturer who’ll be ordering serious volumes of such things.
