Just wanted to report back on this deal as I went through with it. The two L lenses are in pristine condition 9.5/10 by my book and from the date codes of the lenses, they were purchased together with the 1Ds MKii. So if the lenses weren't being used much, the camera body shouldn't have been either.
The rubber parts of the camera body, however, exhibits some greyish white color rather than solid deep black. I'm not sure if it is due to aging or anything else. But the rest of the camera body is fine, shows not signs of heavy usage.
There are people interested in buying the two L lenses I got from this deal from kijiji so I'm confident the 1Ds MKii body will not cost me more than $1K, most likely less than that. So far, I have to say I'm happy to have gone through with this deal to jump into the world of full frame. Thanks everyone for the advice you've given me thus far.