Product review (1 stars): This part is designed to break.
I have had my gas range for less than 30 months.  Although the knob "feels" metallic, the knob and stem in the back are plastic.  This stem slides onto a metal stem on the range.  There is no way the plastic will hold up against a metal stem.  I've seen prices from $53 - $93.  I have to replace all 5 that have a cracked or broken stem.  It would be so easy for Samsung to re-engineer this part to last forever by making the stem on the back of the knob part of the round metal plate that screws into the back of the knob.