I've used the butterscotch from Wally World and it came out great. Cherry from there also, but it ended up in an overload batch so I don't know how great it will end up being, read others had good luck with it though.
At Wally World it was reported to be in the art supply area which is near the sewing material area, which is where I found it on an end isle rack right next to where wedding supplies where. I just figure it's a cheaper way to sample flavors and then if I like them
buy them in bigger qty. from Loranns.
As for food stamps don't know, but if baking supplies are covered then it should be (i.e. cake mixes, etc.).