Actually, the fully-loaded cost for a PhD student is $75k-$80k / year (ie the amount charged to a faculty member's grant). You have to remember, PhD students' tuition is usually incurred as part of the cost since they're working in exchange for (1) a minimally-viable living stipend and (2) fully-paid tuition.
We had two PR2's in our lab (Georgia Tech's Healthcare Robotics Lab). There were ~2 people working on each at any given time.... so the $$ makes sense. And the PR2 was a great platform!
Source: my work on the PR2 http://www.hizook.com/blog/2010/10/16/pr2-robot-autonomously-delivers-medication-using-uhf-rfid-live-cnn
The wages of sin are unreported.