My current audiobook when commuting and such is The Last Lion: Winston Spencer Churchill: Defender of the Realm, 1940-1965, the postumous completion of William Manchester's three volume biography of Churchill. As with previous volumes, it's a bit sprawling (telling the story of Churchill's life means narrating a lot of what was going on with world history generally, especially during World War II, which takes up much of this volume) but never dull.
I'm currently in early 1941, with the Lend Lease Bill working its way through congress and Britain waiting anxiously to see if it passes before the empire goes bankrupt and can't afford to buy much needed arms from the US. The book throws out a few prices: A Thompson sub machine gun cost $200 in 1941 and a B17 cost $240,000. That got me wondering what those amounted to in modern dollars. Result: Putting the 1941 to 2011 conversion into an inflation calculator produces a Thompson sub machine gun cost of $3013 dollars and a B17 cost of $3.2 million. By comparison, the modern M4 carbine (which combines the function of the WW2 era battle rifle and sub machine gun) is roughly half the cost of a WW2-era Thompson at ~$1500. However, modern military aircraft are far more expensive (though obviously also far more functional) than their WW2 era ancestors. The modern B-52 heavy bomber costs the Air Force about $80 million per plane, while the B-2 stealth bomber costs over $700 million.
This also underscores the extent to which World War II was a war of industrial production. 12,731 B-17s were built. Only 744 B-52s have been built in their 50+ years of service and only 92 are currently operational. The fancier bombers are far fewer in number 100 B-1Bs have been built and 21 B-2s.
Of course, part of this disparity in number produced has to do with capacity. The B-17 could carry a maximum of 8,000lbs of bombs, and that only to a target less than 400 miles away. The B-52 carries up to 70,000lbs of bombs and can make round trips out to targets up to 4,000 miles away.