Good price it will make an awesome morphos box
I agree that the price is pretty good for that model PowerMac, even though it does not come with a video card. I suggest getting a FireGL X3 (think that is the right model name) with the Radeon R400 GPU, if it can be found in a PCIe format.
As for both of you claiming that it will soon be supported by MorphOS, I have not seen any official (or even unofficial) statements by anyone that support for the Quad Core G5 PowerMac has been promised, or that any work on such a port project has been started, or will be started any time soon.
I agree that it is logical to expect such a port to eventually be done, but Mark "Big Foot" Olsen and maybe a couple of other members of the MorphOS Dev. Team would first need to obtain that model to work on the port of MorphOS.
Better to not advertise that it will be supported by MorphOS to any buyers, until you have some confirmation that such work has been promised, or started.
Still a good computer though. If I lived in the area where you are, I would consider buying it and I really don't need any more computers right now. Good luck with your sale.