Most medium format film costs less than $6 per roll of 120.
And if you buy enough chemicals to do 100 rolls but you only develop 1, then you're still developing 1 roll cheaply -- you're just wasting the other 99 rolls worth. Shelf life of 1 month?? That's crap, I've been using the same packet of xtol for around 4 years.
The question of what you do with a developed slide or negative is a different story. For me, I own a drum scanner, I scan them, I get a digital image. You can get a cheap desktop scanner that is nice enough for web sharing, and get pro scans for the occasional print. For black and white I print a couple of them on my own, usually using alternative processes like cyanotyping.