Vitamin B12 is available for purchase online through B12-Shot.com in the form of a topical, an injectable, a needle application or as drops. As of August 2015, prices range from roughly $10 for ten shots to about $70 for 100 shots.
Before purchasing B12 shots, you must decide which type of B12 works best for you: cyanocobalamin or methylcobalamin. The first type of B12, called cyanocobalamin, is a synthetic form that is often cheaper and easier to come by; however, your body must convert the cyanocobalamin to methylcobalamin before it can actually use it. Methylcobalamin is the natural form of the B12 vitamin, making it easier for the body to utilize, but commanding a higher price, notes Vitamin Injections.