Honestly, I'd recommend oDesk.
I've hired several workers, for likely similiar mundane boring work, full time for only $200/mo for this kind of work.
My recommendation though is to make sure that you get the RIGHT person.
I always create a simple straight forward test job for everyone, and try out as many qualified applicants as possible. That way if one person fails in the future, I've got a couple backups.
The small test job is essentially a gig thats one or two parts of the "overall" gig.
Finally, hire and fire quickly. If for some reason the person that you end up hiring sucks, move on quickly. Don't take the excuses. Sure things happen in life, but often thoes can be a good indicator of future work habits.