Although I completely agree with having "professional" help with saddle fitting, it will much more cost effective to bring the horse to a good tack shop (not one that only has a few saddles but one with many to choose from). I don't know how much having a pro bring many saddles out to you would cost but I would not be surprised to learn that the cost is close to what you have to spend on a saddle to begin with.
Again, thinking about cost, a synthetic is a very good option. Even used, a really nice leather one will cost more then your budget. Whatever you do, DO NOT fall into the trap of buying one of those package deals you see on ebay or even in the catalogs that sell for <$300. They look attractive but they are Asian made and the trees and the leather are of very poor quality.