The Costco buyers are all really quite good; whatever they are doing, they manage to fine really good suppliers for most things they carry in the store. The SoCal locations all carry really good mangoes when in season, rivaling one well known heirloom producer (Wong's...or maybe they buy from Wong's...). A local chef tried all sorts of strawberries from various farms for his line of ice cream, and concluded the Kirkland ones were the best bang for the buck...