The Mac Pro has gotten more and more expensive in each generation to get mid range specs. When we got our 2008s, the cheapest one, I believe was $2,700 or maybe $2,500. The top end iMac is faster in single CPU than any Mac Pro you can buy. It's not like the CPUs are represented by this thing but it is possible that there are very specific workloads for which they're better at doing a task.