ISS Costs

How does a radiator cost $390 million dollars? Is this just gov't
purchasing policy (i.e. $5,000 Pentagon toilet seats) run amok or is
there so much specialized engineering, R & D, overhead etc in this
price?

Or does this incorporate the cost of the shuttle launch?

Could something like this radiator be made by a small machine shop
for a few million?

"The main goal of this fourth flight of the year is to attach a $390
million truss segment to one already bolted to the ISS. Known as S-
One (S1), the 45-foot-long (13.7-meter) truss holds three radiators
and much of the plumbing that will be required to keep the entire
complex cool once additional modules and power-generating solar
arrays are added in the future."

http://www.space.com/missionlaunches/sts112_preview_020930.html