Thanks everyone -
As Scottish Captain (and doubtless everyone else) inferred, I was trying to convince myself that I could make do with a used G5 as my next computer, for obvious sticker-price reasons.
Strangely, my wife is urging me to pay up for the new model, while I am imagining all the beer and RAM I could buy with the price difference.
Irony of ironies, I was never wild about the G5, which is why i hung onto my G4 for years, always intending to skip the G5 and go to whatever came next. Now the time has come, I'm having second thoughts....
By the way, and apologies for changing the subject, what's the deal with the $600+ RAID card in the Mac Pro? What does it do that the OS doesn't do? I am sitting here with RAIDed disks on my G4 PowerMac, having used nothing more than Disk Utility to get going. What does the Mac Pro RAID card bring to the party?