Grocery stores are the way to go.
The cost of the food at grocery store prices is laid into the cost of the cooking day and what the client is charged. It seems a little cost prohibitive to pay retail prices especially since I know the markup grocery stores make. The information you get from a personal chef association tells you about the nuances of being a personal chef. And the certification offered by one of the personal chef associations has little or nothing to do with the way the ACF certifies its chefs. Certification for personal chefs is totally unnessary.