We have a couple of those large feeders that we fill with cat food, and another large one for water. That way we don't have to have someone come in every day. My Dad usually stops by every couple of days to make sure their food hasn't run out, to clean their litter box, and to make sure they are doing okay. Luckily for me, my Dad helps out for free, so I am not sure what to tell you about how much to pay. I would recommend getting some of the feeders, so you won't have to have someone come in EVERY day.
Also, maybe check in your phone book for a pet sitting service that will come to your home. They will probably be more reliable than just a neighbor kid.