Perhaps one of the better sunset "deals" on Maui, from 5:30-6:30 pm entrees are "Buy One get One Free" at Bistro Molokini at the Grand Wailea hotel. (Entrees range from $30-40)
The photo above is the view you get at sunset. The terms and condition is: You need to book ahead (no walk ins) and need to mention the BOGO offer at that time. Tip: Ask for a seat "by the rail" to have an unobstructed sunset view.
Tip 2: the sun sets around 5:30 in the fall
Tip 3: Given the shape of the island you can see the sun actually set in Wailea from July through Dec. thereafter the daily sunset is "hidden" behind the rocky slopes of the surrounding cliffs.