G4 towers are very expandible and you are paying for OS9 boot capability. From what I hear... G4 sales are still significant.
Actually, they've only sold about 8,000 of them this quarter.
Are you talking resale or new? I'd say that the reason the prices are still hanging in there is because you can still run Mac OS X and apps quite comfortably. they hold their value that way, rather than how a PC needs more and more upgrades as the OS evolves. I use OS X on a G4/450 100MHz front-side buss EVERY DAY ALL DAY and it works fine for the most part. imagine being HAPPY running XP on a 400MHz P4 (which they never made that slow, but you know what I mean).
Also, depending on the type of functions you do, a dual G4 can sometimes beat a single G5. Also, keep in mind the other components in the Powermac, which would definitely contain Firewire, and probably also have a DVDRW drive.
I think the prices for a new G4 at ~$1750 is pretty reasonable (for single 1.25Ghz) & $2250 for a dual when you consider what the prices were pre G5. When peole post their G4s for sale here I calculate what it would cost to upgrade to an equivalent new one and the new one is cheaper almost every time! plus you'r egetting faster ram and FS Bus
I just wonder how much longer they are going to be available as I want to get one next year
<edited for fat finger spelling>