1. Virginia Tech used Apple G5. How cheap it is only depends on the quantity discount from Apple. Don't you think it's stupid to call it "cheap"? If they chose AMD Opteron it would have been cheapter.
2. It takes virtually no effort to build the so called super computer using either PC from junk yard or "off the shelf" G5. They all suffer from the same problem, the communication cost, which makes them not suitable for tight coupled problems that required heavy synchronization.
3. Unless Chinese has its own IP of the CPU core, it will be difficult for them to design on chip inter-connected multi-core architecture or vectorized computers. Just think about how difficult it is for Intel to move memory controller from chipset into CPU. It's all about engineering work. They may have already known exactly how to do it. But it still requires a tremendous amount of effort. Now Chinese has demonstrated the capability of developing quite efficient working general purpose CPU. It's already officially a player and it opens all kind of opportunities.
4. China will be a serious player. Don't be surprised that in the future the CPU is not sold be quantity of pieces but weight in stead because it's so CHEAP! Got it?