I would questions how the independent seller is able to offer a 1 year factory warranty- those are usually offered only by authorized dealers. The "normal" going price for a used 10D is 1000-1200 USA dollars, and the lens is at least another $100 on top of that. If it sounds too good to be true, it *usually* is. I can't guarantee either way, but it sounds fishy on two counts to me: 1) price too low 2) factory warranty from a private seller.
If you do buy it and it comes as advertised for that price, I'd be interested to hear, so let us know