One of the places I always turn to when trying to save money is with purchasing. This is a choreographed balancing act: Not too much, not too little, not too early, not too late.
And then there's the purveyors.....
My personal preference is to only use the "big boys" for standard stuff like fryer oil, fries, brand name condiments, and some drygoods. I will always use small indie produce merchants for 90% of my produce--thier prices are waaaay better than the big boys, quality is the same, and they don't give me no attitude.
Dairy--milk, especially cream, butter, eggs, and cheeses are almost always cheaper at Costco or supermarkets than from purveyors. Once a week I'll do a "costco run" and pick up a week's worth of dairy, canned pop, and some drygoods. While this may take up two hours of my time, the savings--almost a dollar cheaper per gallon of milk or quart of cream--can not be ignored.
Beef from a beef supplier, chicken and poultry from a poultry supplier, prices are better than the big boys, and quality is just as good if not better.
I've got an Italian wholesaler very close by, I get my olive oil, pasta, tomato product, and "italian stuff" from him. And every time I visit him, I see the big boy purveyor's trucks loading in his parking lot--not unloading.