Then he has, in essence, bought an all-show-and-no-go kind of machine. At least he didn't get the $2,100 macbook air, that would have been worse. Its his money, however if he mentioned power then he should have seriously revised his options or at least got a little bit of knowledge before coming to a decision. Did he really need that retina display? probably not. For the same price he could have got something more in response to what he wanted. being power in this case, he should have got the 15" macbook pro and replaced all the internals with that of the 13" retina mac - all for the extra power.
But then again, since his previous computer was a macbook air, i guess you could see where the sources of ideas are in his decision making. However i would have still sugested getting a non-retina macbook pro, though this time it be a 13", and replace the internals with those that would be in a retina macbook pro, at a smaller price.