Today I swapped out the mechanical disc brakes on an MTB for hydraulic ones, and
I was really surprised at how cheap Shimano's budget hydraulic disc brakes are
considering how well they perform.

The brake caliper MSRP is 1,695 yen,
and the brake lever MSRP is 1,138 yen, so
the brake hose actually costs more than either of them.

Since the frame-mount infrastructure is the same between mechanical and hydraulic,
if you don't mind the minor extra maintenance work involved,
honestly the pricing makes you wonder why anyone wouldn't go hydraulic.