That's basically mine. The one I got cost about $220 and came with an additonal 6x9 mask. The ruby window is fairly dark. Not the best thing if the film you're testing with uses black writing on black paper. Other then that it's simple and works.
To order direct you need to go to the Shen Hao website and send them an email. I don't know how much shipping on just the back would be. It makes sense if you're ordering a camera from them since they don't charge much more to ship the back over just the camera. But if all you want is the back the shipping might eat up some of the savings.