104 key mechanical keyboards have 104 buttons and may go for $30. Maybe it is the knobs? But you can get a midi keyboard with 8 knobs, 49 keys, 12 pressure sensitive pads for ~$100 (but maybe it wouldn't last in car cabin heat).
There are also reliability expectations. If I need defrost because the windshield just fogged over, it better activate when I turn that knob on my sixteen year old car. And so far, it always has.