Think Dual processor (Not dual as in core but dual processors sockets on the motherboard) Xeon with 64gb of RAM with 4 graphics cards.
That's more of a workstation that a personal computer. Crazy people with lots of money I guess.
Sounds like he should go buy one of apples mac pro towers even though it is a mac but those towers have insane ability to have parts swapped on them for much more powerful but I do believe it is impossible to take their processors out though.
Edit: Where in the loving world do you have 15k to spend on a computer you can buy a small car brand new with that.
Edit2: Since my iMac model is incapable of prtscreen due to bootcamp x64 is unsupported I had to take a picture with my phone but this is what I got out of the best mac pro tower apple has to offer.