I would suggest an alternative to the OP - get a high-level player, like a college player, to hit with you. The cost is much less. By carefully observing him and asking the right questions, you can learn a lot.
For example, I am learning how to handle side spin by hitting with a poster on this board (who is not a college player, but a high level rec player). I am also observing how he adds the side spin - which I can then correlate by watching the pros on Tennis Channel.
There is no way a coach who himself plays 4.5 or below is going to be able to give you that kind of experience.