It was about $175 if I recall correctly. Installed it myself, wasn't very difficult. Had to drill 3 holes under the sink for hoses to go in their places.

I think the drill was the only tool I needed. Replacement filter sets are around $80 per year, so the cost over time / per day is very small. I drink water from it several times per day.

EDIT: Oh yeah I needed some wrenches too for the T-junction connection. You have to turn off your water to the sink, then wrench free the pipe and install the T-junction in between, to tap the output for your filter system.