For those looking for cheaper breakfast (and food) options, here are a couple of other good options if you have a car:
1. There are many fantastic farmers markets throughout Maui, including a couple of ok, smaller ones in Kihei (and a better one in the mall near the airport), that can have incredible fruit -- some far better than you can get even at the breakfast buffet. They will often have some combination of fresh pineapples, bananas, longans, lychees, passion fruit, star fruit, coconuts, and several varieties of papayas and mangos (some of which are have been some of the best I've ever had). Only note for some of the varieties of fruit is you'll need a knife to open them and silverware to eat (which I'll bet you could get from room service or just buy at the store). Here is a link to a list of Maui farmers markets:
http://www.gohawaii.com/maui/guidebo...arkets-on-maui
2. If you have a car, there are many, many more affordably priced restaurants and bakeries in Kihei. Just yelp it and you'll find dozens. Same applies for lunch / dinner in fact -- there is a great food truck scene that has developed in Hawaii with often as good or better tasting food than the super pricey Mama's/Merriman's type places at one-tenth the cost. Again just yelp it and you'll find dozens, including several in the Kihei/Wailea area. Personally I go to the fancier places for the view/service/ambiance, but some of the best food I've had in Hawaii has been a $6 plate lunch, locally flavored taco, Luau pork, Huli Huli chicken or similar unique item from a food truck.
3. Even the normal grocery store or Costco is a good option for great fresh produce (papayas and pineapples in particular tend to be good even from the local grocery stores) plus other typical breakfast items (pastries, yogurt, cereal). Only warning is the refrigerator in the room is a stocked, drink fridge, so it doesn't get as cold as a normal refrigerator and is full of free drinks (though I hear it's less full than it used to be!) A good option if you're getting cereal/milk is individual sized, shelf stable milk, which while more expensive is much less likely to go bad (and is still cheap compared to any restaurant). I'll bet you could also request a standard mini-fridge since typically most hotels have a handful of these. Again you'll need plastic bowls or cups and spoons for this, but any local grocery store will carry that.
While the food at Ka'ana Kitchen is fantastic (and I'd recommend going there for at least one breakfast and one dinner just to try it), you can have an equally delicious experience and really taste the local produce/flavors with a little bit of effort for a lot less money.