Frank, there are a lot of reasons for the high prices, including declining sales volume, the German wage scale compared to Singapore where they moved their production of 35mm cameras, the money they dumped into their ill fated Rollie SL66 which was never able to compete with Hasselblad, the shift of the pro wedding and newspaper shooters toward 35mm (and now digital), the fact that a Yashicamat was "good enough" and cheaper to just replace than to get a CLA on a Rolleiflex. In the end though, I suppose they just were no longer fashionable.
Still, it's a versatile machine. A 75mm lens on 120 is about the same coverage as a 35mm lens is on a 35mm camera, figuring cropping to 8x10 proportions. The 75 or 80mm lens allows cropping enough for a decent head shot, the field of view of a 90 on 35mm film. Dust on the larger negatives is less of a problem.
The majority of public relations or news shoots could be done on a 12 exposure roll. For a generation making the switch from sheet film and 4x5 press cameras it was a challenge figuring out what the hell you were going to do with the remaining 8 or 9 shots on the roll after you knew that you'd nailed the moment.
SOMEBODY must be buying them again. There aren't as many used TLR's for sale these days and prices are creeping up again. Oh crap! I'm talking myself into picking up a brick of 120 TX again.