I've wanted an RB67 ever since I first became aware of anything larger than 35mm in about 1988. Always far far too expensive. Then about two years ago they started to really drop in price and I bought one (mint RB67 pro-S). I was just going to keep to one lens (90mm), but one thing led to another and now I have a 50mm, 65mm, 90mm 140mm macro and 250mm, the latter I bought new for £190! Unbelievable! Then someone GAVE me an old RB67 Pro! I had to replace the foam in the backs and the mirror box but now it's good as new. I still can't believe that a camera that is responsible for probably 25%(ish, ok wild guess) of all fashion and advertising images over the past thirty years is selling for next to nothing. madness, but happy madness.
By the way, they are heavy, but if you go out with just one lens, two backs (colour and b&w) and a good tripod, it's less weight than two modern SLR's and a suite of lenses. I actually carry less when out with my RB than I used to with my Nikon kit. And the 6x7 images will still blow anything digital out of the water. Oh, and you get to learn all about metering, exposure compensation with extension, hyperfocal distance, reciprocity failure and a whole host of interesting things into the bargain.
As John Lennon sang, 'strange days indeed'.