On the other hand, I've just come back from Arles, where I shot 518 pictures on a 9 day trip, not counting the ones I deleted on the spot: call it 15 rolls. Quite a lot were 'notebook' pictures: gallery interiors, Artists' Statements and commentaries, etc., where post processing wasn't important. Going through 500+ pics is tedious enough: I can't imagine 350 a day on a regular basis. What do you do with this 'complete record'?
I don't argue with your cost analysis: $7000 for an M9 is 700 rolls of 36-exposure at $10/roll, the least you're likely to pay for decent film and processing, and over 5 years that´s 140 rolls/year or a 2-3 rolls a week. I'd hope for more like 10 years or even 20 from the M9, though, at which point the cost is trivial, the more so as where I live, it's more like $20-$30/roll for colour film and ref prints. It's just that I can't help wondering why you take quite so many pictures; what you do with them; and (most of all) how you find the time to review and process them.