I have been doing some reading on the space race, and I have found myself to be very interested in the effects it had on the the U.S and the USSR. I am particularly interested in the economical aspect, especially since I can find very few credible source concerning the USSR. So in what way did it effect the countries? Was the expenses one of the main reasons for the downfall of the USSR?
At the peak of the Apollo program NASA got approximately 4.5% of the US federal budget, or just under $6 billion in 1966 dollars. Here's a NASA budget document as my source. By comparison the DoD's budget that year was $63 billion according to this State Department report. So, on the US side of things the economic cost of the space race was relatively insignificant compared to overall government spending.
This CIA report claims that the Soviets were spending a bit more than half as much as the US on space exploration in the first half of the 1960s. Another CIA report estimates that Soviet GNP at that time was about half of the US's. So, assuming these figures are roughly accurate the USSR's space program would have had a bit more of an economic impact but not dramatically more.