I think the 1GHz is FSB and from what I know the memory doesn't really need to have a "compatible" speed, so DDR333 would work.
As for overpricing, the 970 is supposedly cheaper than the G4. The rest of the system, from the optical audio I/O, trough FireWire400/800 and USB1/2, PCI-X, Serial-ATA and the supposedly sexy and cleverly designed case, I do think that a PowerMac does deserve a bit of a price premium (as do many Apple products). It's simply that all the components along with the added special manufacturing cost more.
Now before people start with "software incompatibility" (-Duh! It _is_ a different platform after all, so it won't run on x86 and wont run x86 software) or "Opterons are cheaper and faster for the money" (Do I see Dell selling Opteron workstations? No, the PowerMac is not really a consumer desktop, hence the price) or any other often-heared Apple bashing, because it's, well, Apple I would like to say that I am happy with my PC as I'm happy with my Mac. I can work on both and get my work done and that's important to me. And iTunes is great.