Not that this helps you, but it's not specific to Bronica. KEH's inventory has shrunk across the board in the last year or two. There's still lots of Hasselblad and Nikon gear on offer, but there are no RB67 bodies listed, and the listings of Pentax bodies and lenses are less than a quarter as long as I remember them being in 2009-2010, which is the last time I was seriously looking. It makes me wish I'd taken advantage of the great bonanza of bargains. Ah well.
I hope that today's pickings are slimmer because all those cameras are in the hands of happy shooters, or better yet that Brian Legge's hypothesis is correct and that we'll see a seasonal expansion of inventory around when I go on a shopping spree this summer.