The low search volume notification doesn't do any harm to your account. If you see from the search terms report that there is traffic on those keywords, then its fine. If you are only servicing that 15 mile radius, without being an expert in the industry I would say that it sounds weird if there are many competitors all paying the high CPC. Can it be that there is just only 1 and you are battling for rank 1? Maybe switch to manual bidding and test out lower positions? In any case, if a search query works for you, you should add that one in exact.