I should preface this by saying I wasn't entirely happy with the one fitting I had. But I made a point of finding a saddle that worked before I went for the fit. In fact, the saddle was a large part of the reason why I decided the fitting was necessary - it completely changed the way I sat on the bike.

I did know that the shop where I had my fit done didn't stock any saddle that had a hope of working for me. Maybe if you were getting fitted at a shop that had a wide selection of saddles in sizes and shapes that you think might possibly work for you, you should get it all done at once.