For server administration jobs, never hire a person online. It's high security risk, unless you have proper backup mechanisms and systems to remotely log each and every activity even a root user does.
Always a in house staff is worth every penny. You don't know how secure is their system, even if that person is trust worthy.
Even in house, we log every activity our admins do. Infact they are also aware of it and due to that reason, we get a honest approach from our staff and not to hide their mistakes, if any