As a postscript to the B-17 story (and in response to various queries),
here is some cost information on the B-17 Fortress.
According to Peter Bowers's *Boeing Aircraft Since 1916" the cost of a
B-17G when built in mass-produced quantities in 1943-44 was:
Airframe $127,069
Engines $38,483
Propellers $11,900
Electronics $9,040
Ordnance $6,342
Miscellaneous equipment $45,495
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Total: $238,329
Sounds like small potatoes today!
Source: