How much are ibook G4's worth?

My friend has a iBook G4 1.07GHz. 1.25MB, with Leopard 10.6.4 Leopard. Microsoft Office 08, iLife 08 and other nice programs. He wants to sell it and upgrade to a Macbook. He is also including a 250GB external Hard Drive with Firewire cable, Family Pack of Leopard OS disc and a Sportfolio 2 Carrying Case (Brand New).

The only problem is he don't know how much he should sell it for. So I decided to post here and ask for a little help. I'm not that much help to him because I'm new to the Apple/MAC Family myself. Therefore if anyone can help us out it would be much appreciated.

Thanks