Thank you for your replies - Keith's post about changing genres/purpose made me think: that's a big moment in photographic life.
My usual - commercial - needs were all satisfied by 24x36 and 6x6, and for years that's all I ever thought about using, apart from the occasional notion for 4x5 (for still life) which I never followed up, knowing it would only lead to massive investment in studio lighting I didn't really need for anything else. Life went along smoothly enough without it.
Then I listened to the siren voices of stock agents and believed that I simply had to go 6x7. So that was what I did. Twice, on Bronica and then Pentax, the latter just as digital was coming out of the woodwork. And very shortly afterwards, the stock world stopped giving me anything worth shooting to get. So hey ho, all change, back to Nikon!
These desperate departures into new things have left a mark made all the deeper by retirement and the total loss of photographic income. As a result, I now own just two digital cameras, a D200 and a D700 with a selection of old and new glass. (I also have a seldom-used F3 that now can't use my latest 1.8/50 G Nikkor.) Surprisingly, I find that the old D200 gets by far the more use, along with the new af 50mm, if only because of the sorry state of my natural vision and lack of a split-image finder in either digital body. The 50mm makes a nice, light 75mm on the cropped camera. It suits my non-pro life. Chinese plastic, anyone?
Regarding Leica: I never owned one for various non-finance-related reasons during the time when I was working; today, ironically, I really do covet an M of some kind, despite the very shortcomings which kept it away during my pro days! Perverse? Damned right! I think my reason is almost historic: it feels like a missing link in any serious photographer's experience not to have or have had one.
But, I think the price is crazy. I simply don't buy into the belief that it has greatly superior build qualities - after all it's a marque that has had one helluva bad track record since its digital start, at least in the RF line-up. From shutters to sensors it's been a lot of bad news. With luck they are over that now, but then you come to lenses, too, and whilst I personally did observe differences in quality/look printing from M3 and a 21mm of some type for my very last employer in '65, it's not something I think shows in any digital reproductions I have seen. I don't have any idea if Leica is profiteering or is simply woefully inefficient in the manufacturing department; but they sure can sell dreams, even to seasoned old pros such as I!
All of which said, if I thought I could still afford to lower the bank account that much, I'd get one now. I think it's a decision not of the head but of the heart, unlike most other camera decisions.
Rob