My experience with allergy testing by most MD's is that they only consider IgE to be a true allergy, and they discount IgG as an allergy, and often don't even test for it. I have had two gastroenterologists tell me that although I have an IgG to gliadin (one of the molecules in gluten), that I don't have an allergy to gluten.
If the only thing your being tested for is IgE to foods, I expect you would already know you had this type of allergy. It is like an anaphalactic response to peanuts...etc. Unless s/he is doing a full panel that includes IgG antibody testing, I would think it is possibly a waste of time and money. So I would get details on what the test actually looks at in order to better evaluate it.