In point of fact, looking at the entire spectrum of conflict-pertinent technologies, from production to comunications to aviation to metallurgy to chemestry/ordinance, etc, it is clear that the Brits and Americans had a major (some would say "vast") technological advantage over their opponents.
Well that is why Italian/German scientists (some of whom were clever enough to leave before Hitler/Mussolini) were hired for the Manhattan program, the space program, and so on.
Look at the list of nobel prizes from 1900-1945 (physics, chemistry, and medicine only - literature and peace won't win any wars for you):
Germany 36 Nobel prizes
USA 12 Nobel prizes (2 of which to people with very German sounding names)
In 1945 the USA plundered the German patent office before anything else. That's why Aspirin is cheaper in the States today than it is here (they revoked all patents without Germany).
The nukes themselves were not that expensive but the whole program to develop them was costly both in terms of funding and time.
600 shields, if I remember civ2 correctly - not cheap!
I think is was the lack of supplies that broke the German's neck. My grandfather fought the Americans in Italy with the Wehrmacht (helping the Italian Fascists there). He said Germany lost the war because the Americans had the material to shell a front region for days before going in whereas the Germans just didn't have the artillary ammo. Rather demotivating. They all deserted before long because everyone knew that rations in US/British POW camps were better than in the Wehrmacht (plus you only risked getting shot if you were caught - otherwise you kept risking your life every day).
I think t was not a question of tech in Europe but the faltering German economy/industry. There is a limit how far forced labour can take you in the real world.
Anyway: I am so glad we lost!