I haven't seen any deals lately on any Fisher tuner, save one FM-50 I bought as a parts unit. Even the 101-R (and it's big brother then 202-R) and KM-60 are bringing rather extravagant prices.
The FM-200 must have had a manufacturing window about as wide as a gnat's butt. It's the only mono Fisher tuner I've seen with the stereo-era extruded, grooved faceplate that matches the MPX-100 and the other multiplex-era components. My guess is that it probably only existed for a short while in 1961 before the multiplex standard was established and the FM-200-B was introduced.