Whenever you buy medication, try to buy the generic brand, orno name brands, if you are not allergic. This will save you alot of money. Check the labels of both the brand name and the generic. For the most part, they are the same. Shop around at different stores in your area. I have found that the dollar stores carry alot of inexpensive medicines, including vitamins, that are about half the price of the brand name products. Even the local drug stores carry generic brands. Depending on your need, I feel sure these generic brands will be able to deliver results.
I would like to share some other bits of advise that will save you potential problems. Follow the directions on the bottle. Never increase the amount as overdose is possible, just as with any other medication. Buy multivitamins instead of individual vitamins. They provide the same benefits and will decreases the possibility of error. You get more for your money this way as well.
One final thought-Remember, there is no substitute for a well balanced diet!