The blood
test that I have had
for food allergies is called R.A.S.T, it is the best one I know of. There are many food panels, and unfortunately, they are not all grouped together, so, they actually need to run many, but, they will run them from the one blood draw, at least they have mine.
I do not remember how much it costs, but, I do know it depends on the lab and how many they do, you could always call a near by lab and just ask, that might be your best bet.