I wouldn't.
Personally, if you're paying $575 Canadian, that 10D had better be in immaculate condition, with very few photos taken with it. If you're going to pay as much as what he's charging (ie: as much as a trusted retailer does), it should be in even better condition, because retailers generally do charge more, not personal sales like this. I don't know how you can find out the number of photos the camera has taken, but I'd surely want to know before I buy it.
I'd rather buy a new Canon 350D if you're only considering Canon, or the cheaper Nikon D50 if I was going to buy the body only.