1D Trade In Value

Hello everyone. It has been a long time since I have been a part of dpreview. I may be trading a mint 1D with a very low shutter count to someone with a 5D ii, also with a low shutter count. Does anyone have any ideas or resources that would help both parties involved in the potential trade?

My main cameras are 1D mkII and 40D. I shoot sports, wedding, and portraits. I have EF lenses except for the EF-S 17-55. I will also be looking to upgrade the mkII to a mkIV later on.

Thanks,

Richard