Well what a really good horse trainer will do is get you involved. They want to see how you handle the horse and see what they need to do to correct his issues.
Your horse needs refinement and correction so it shouldn't cost as much because he doesn't need to be started and taught how to do things. So you may get out a bit cheaper that way.
Another good step is indeed to consider investing in Clinton Anderson or another natural horsemanship trainers DVD's. It can be very helpful to learn how to do a lot of it yourself espeically if you plan on owning horses in the future as well as now.
At the very least Id see if you can find someone to come out and evaluate the situation and give you some advice on what they think they can do.
Don't be afraid to ask other people in your area who they might know.