Wired up my jacket liner last week and had a chance to try it out in 33F temps this week, works like a charm.
Picked these up at Rockymountain ATV for $15 also. Wore my summer gloves on the same morning and was quite comfortable...no heated grips on this bike.
Total invested around $70.
Wire was free
$15 - mitts
$35 - Tourmaster heat controller (bonus, ordered the single controller and they send a dual)
$14 - battery harness
$6 - Tourmaster extension cable used as plug on the liner.