I can totally understand why it went for $2700. If someone is a 'professional' collector, this is a very rare find. A brand spanking new top of the line iMac G4?
It's just that I spend that kind of money or more on my rMBP, but never on this as I know I can get the machine for a fraction of that price.
But, again. If you really enjoy collecting those and are willing to spend the money. I don't see why not?