It was less than $80 back in 2009 and should be closer to $100 right now (I found one shop selling for 54 GBP and one out of stock listing at $75 but it's hard to say how old that is).
The M150 was my daily driver for a few years, and even now it's probably the best pen I have as far as something that comfortably fits in a shirt pocket while being a top quality piston filler. Funny thing about products like this is that prices inflate at staggering rate.
And yes, wood, leather, cloth, specifically any material that has cellulose fibers, which Noodler's black is formulated to chemically bond with, thus the permanence.
Just yesterday I was labeling some cloth bags with a TWSBI because, again, it writes the same on almost any absorbent surface, a sharpie smells horrible and can't get you a clean line (actually they were cloth bags to hold my new set of Falcon stems). Fountain pens just don't write on plastic (The Pilot Multi Ball works amazingly well for that, the ink seems to dry into a hard resin: http://www.jetpens.com/Pilot-Multi-Ball-Rollerball-Pen-Fine-Black/pd/2760).
Every kind of writing implement has it's place, but if a given surface can work with a Fountain Pen then that's probably the best tool for the job.