I'm curious about the economics of this machine.

Wikipedia says it could be rented for $1485/mo, and the average salary in 1956 was $3600 or $300/mo, so it would have to replace 5 people (engineers must have earned more), if you don't count the extra cost of software, power, and maintenance.

I remember from a book on Richard Feynman that a classroom full of bright students was about as fast as the computer the Manhattan Project got, except, of course, the computer didn't get tired.

Not really a computer though - they didn't exist in the USA at the time. If I remember correctly it was a series of IBM calculating devices chained together.