Re: $20,000 hammers
An exploration of the $30,000 toilet seat (which was for an aeroplane) is in "The Darwin Economy" by Robert Frank.
If I rightly recall, it was so expensive because it had to be a funny shape to fit in the only available niche for it in the plane, they only made a very small number of them and they had to be fire-proof, lightweight etc because they were in a military aircraft that was built with the expectation of being shot at.
I seem to remember that it was really good value (i.e. saved more than it cost) because it greatly increased the endurance of the aircraft, meaning that less time and money was spent on takeoff/landing and flying to the area, and because fewer aircraft were needed to do the job (which was surveillance of some kind).