I paid close to $200 for my Mamiya Six, but the Zuiko lens is (IIRC) a six-element similar to a Xenon, and the Mamiya is a better known make/model. Mamiya also carried the line a little longer, adding automatic frame counter (for both formats, in some models), and had coupled RF from the beginning.
Another option with moving film plane for focus is the Ensign Commando, but they're less common and, in good shape, at least as expensive as a Mamiya 6, despite being older.