Another point I want to make is that the Russians often use interesting engineering solutions to overcome limitations in manufacturing techniques and materials. Take the SR-71 and MIG-25, for instance. The Americans used titanium to protect the aircraft from overheating when it was traveling at high Mach speeds whereas the Russians resorted to stainless steel. Although it came at significant weight penalties the Russians still managed to achieve what they set out to do. The latter is obviously less expensive than the former.
There is a humorous article by an aerospace engineer on CJDBY on the differences between Russian and American turbojet/turbofan engines. When I have time I'll try translating it.