@ amigadave
It's an iMacG5 PPC iSight 2.1Ghz 20" model as I got for £325 that's the best deal I've seen in months on ebay, just wish I could have collected it as the seller only lives 7 miles away but he said no and it's costing me another £25 shipping and I have to wait till Thurday to get it, crazy or what... 
here's a link to the current ones on ebay
UK Ebay Prices For iMacs
If you keep your eye on them you'll see the silly prices they go for over here and it's always within the last 15 minutes of the sale that thing go mad.
But thats the problem here for folk like myself, if you really want it it's going to cost you... 
(Wish I could get hold of them at the prices you have in the States, could be even richer than I already am... )
I can only sympathize with you and agree that if you want something and don't want to wait while looking around for better prices, eBay will get you where it hurts (the wallet) every time. The best price I could find here for the same computer as yours on eBay was about $350 to $420. Shipping is expensive due to the size and weight of such computers, so buying here and sending it there is not really an option for these models, but if you ever need parts for yours, that is another story.
That is a nice computer for web browsing, Skype calls, iChat with family and friends, listening to music and watching movies/dvd's. When my 80+ year old Dad wanted a new computer a couple of years ago, my sisters and I talked him into buying a used 17-inch G5 iMac from eBay USA, instead of buying a new eMachine with no monitor or webcam, for about the same price. He loves it and is very happy with the switch from Windows98 to MacOSX. You will now have a much better iMac than your 800MHz G4 iMac. Since one sister lives near Auckland, NZ, my Dad likes using the iSight and iChat to see and talk to her from time to time.
If yours is the model I think it is, it should have an ATI X600 graphics card, which gives you a better chance than models with NVidia graphics cards, for a possibility of MorphOS2.x being ported to it some day in the distant future (just in case you want to see what it looks and feels like, the demo is always free, but time limited to 30 minutes before a reboot is needed to give you full speed again). One drawback of getting the G5 model of iMac, instead of the newer Intel Core2Duo models is that the Intel models run WinUAE and Amiga emulation much better than the G5 and E-UAE.
Lastly, I am usually very wary of eBay sellers that live so close by, but still refuse to allow you to pick up your won auctions in person. It can be nothing more sinister than the seller not wanting to bother with trying to arrange a time to meet with you, or the seller has had bad luck in the past where the buyer changes his/her mind after seeing the item in person, or worst case, the G5 iMac is in bad physical condition (or does not work at all) and the seller does not want you to know where he/she lives after the sale, so you can't bother him/her afterward and try to get a refund, or some kind of compensation to resolve a less than perfect, or less than described item. Hopefully you won't have any such problem, but I know how you feel when the seller won't allow you to pick up your item, no matter how close you are to them and you are forced to pay the shipping. Another reason that some sellers will not allow local pick up of your won auction item is because they have added a few pound/dollars/euros to the shipping cost to pay them for their time to box it up and take it to the shipping company and they might not want to lose that few extra dollars/pounds/euros because they did not get as much from the auction as they would have liked to get.
Good luck with your new computer purchase. Now what are you going to do with that G4 iMac 800MHz? It has a very unique case and monitor design, some hate it and others love it. Too bad it could not run MorphOS2.x for you due to the graphics card inside it as well as other drivers probably. 800MHz G4 is plenty fast for MorphOS2.6 and you could have gotten some good use from it for a few more years.
