I've been looking at purchasing an older G4. I've given myself a budget of about $100 give or take some. MDD is out of the question for this price but from what I've seen, but a Mystic, Digital Audio, or Quicksilver are in this price range, depending on the seller. I've seen a few dual processor Mystic machines in my price range at 450-500 Mhz. I've also seen some Digital Audio and Quicksilver machines at around ~733Mhz going for similar prices. Which is the better buy here ?