Where do you think they make Mac parts? BTW, most of the parts , I picked are probably made in Taiwan
At the very least, in the G5 the graphics card, hard drive, memory and the DVD drive are likely candidates to be made in China. They're all industry-standard parts, and those are often made in China. Specifically, I know Pioneer (the drive used in the G5) makes a lot of its DVD drives in China.
Last I heard the new Mac motherboards were going to be built in the US, even if they are built somewhere in the orient I trust Apple's Q/A a lot more than I would trust whoever claims they are doing it for your vendor. You want cheap, fine, just don't try to claim it's equal or better. Cheap is cheap for a reason.