Way to much work. It probably work out cheaper buying a new XBox.
If there is damage on outer-tracks there is most probably damage with there internal board tracks. As this damage was not coursed by normal usage but by a violent physical damage (even if it was not intended).
If some wants to have a go let them, but if they want payment. Then I would only them do if they agreed do it on the condition that you would only pay them if it works. They could end trying to fix it and it wasn't possible to get working again and invoice you for them time other wise. Both of you must agree to this before any work is done.