Actually, Meade and Celestron make thier scopes for less than what the Japanese have been able to do it.
The secret is to automate the construction of the whole scope and sell a lot of them. The primary mirrors are spherical which is an easy shape to make. The correctors are built on special fixures and the surfaces that need to be made on them is again a spherical. The secondary is the worst part and, since it's not large, it's a lot easier to make non spheric than any other part. The rest of the scope is mechanical and is easy to do anywhere.
I wouldn't guarantee that the system is 1/10th wave on every system but they are actually doing a very good job on such a complex system because they are doing so many that the new workers soon learn what is necessary to do the job right. Needless to say, the secondary makers are the most experienced ones, the ones that have already done the work on the other parts of the scope's optics. Finally, they do test a lot to insure that the instruments are all up to the required quality and when you get a bad one, it's usually bad because of shipping rather than basically bad optics.