While I was investigating and building the list of equipment prices - I uncovered a huge historical element in the manufacturing of war machines during WWII. I've included historical values for most German and American equipment when I could find the data (big thanks to those who helped out) .
German manufacturing prior to WWII starting was very efficient. For example, the price of a B-17 is $147,000 but a Ju-88 is $43,000. From what I've read, Germany was able to ramp up it manufacturing a lot cheaper before and during the war due to their process and manufacturing controls. Allied manufacturing companies incorporated a lot of the German manufacturing efficiencies into their own mid-late war. Which explains why a P-51D was made for only $50k in 1944 - which is based on the Bf109 design and manufacturing process. Not to mention the more you something, the better you get at it. Combined it helped reduce our costs - but the Germans were already good at it for years back to the days of the Spanish Civil war when they were already mass producing bombers, fighters, and tanks. So, Germany had a 3-4 year headstart.
When get got them we had German engineers that migrated to the Allied countries work with us in the war departments in the Canada, UK, and the USA ...especially with the Manhattan project, to help improve our manufacturing processes.