Red Tape'd!
I'd selected all the components to build this 16 GB monster for a cost of just under $1k and was trying to sort out all the details for payment when I was told that the University now adds an approximately 50% overhead charge onto any purchase of computer equipment less than $1000. I'd hoped that if we purchased all our equipment from one place and it totaled more than $1000 that would exempt us from this charge, but after talking to the people who deal with the finances, it seems that this really applies to each piece of equipment, not each order. So, in effect, if we buy the components we pay $500 extra, but if the merchant would simply assemble them into "1 x computer" then we wouldn't have to pay it. I'm sure there was some rationale behind these rules, but obviously right now they look insane to me.
So the end result is that we can either pay more somewhere else to get a pre-assembled system or we can try to lobby the bureaucracy for some sort of exception. I had already ruled out the idea of getting a cheap 16 GB system from Dell or probably any of the big computer system makers, but now I'm looking around to see if there are any small time custom computer system builders we could buy such a system from for a little more money.