You'd do better finding a good health food store or specialty vitamin shop nearby. Better selection, plus the stuff you get in a pharmacy is overpriced and you're paying for fillers and artificial colors, etc.
I'm on a frigging first name basis with the people at the nearby Vitamin Shoppe. I've switched 90% of my purchases over to mail order to cut down on costs (shopping around some places offer flat rate shipping if you make a minimum order). I think now I'm saving anywhere from $50 to $100 a month, easy. For me the killer is the advance planning.