Focusing screens for the illusive Contax 645

I still can't believe that I actually did it, but I bought a contax 645 today. I've used one, but it had a split prism in it and compared to my Mamiya 645AFD, it was beyond fast and easy. Now I've heard of paying for the screen to get etched, but I know there was a factory screen. I think I found one (mfs1), but it's $50. Considering how expensive anything contax is, is that a good deal?