I don't want to keep buyung?

It actually sounds to me like she's taking advantage of your friendship to sell these products to you. Most people may make the occasional purchase from these mail order companies, but it;s not a regular occurance. Tell her that the prices are too high, and you can't justify spending that kind of money when you can get better value at local stores.

I think that you shouldn't have to pay that just to help support a friend. Just explain to her that it's just not in your budget. Perhaps if you found a "replacement buyer" for you it would make up for your lost patronage. I have to bring up one issue though. Make sure when you take the vitamins they are a once a day kind of thing...if you have to chew/take 1-3 tablets 2-3 times a day it could actually end up costing about the same amount as her vitamins. If you are taking them incorrectly then you are wasting your money. NOT all vitamins are the same.

You are in the absolute right. Don't feel bad. Just tell her the truth, that it's crazy of you to spend that much money when you can get it for so much less elsewhere. Even if the economy wasn't screwy right now, it would still be a foolish waste of money. If she gets upset or doesn't understand, then I would kiss that friendship good-bye, and realize she wasn't much of a friend to begin with.

Sounds like you need to tell her that your budget simply doesn't allow you to purchase her products as you are not able to meet the minimum requirements. If she's a true friend she'll understand.

I'm sorry if any of my friends came to me with prices like that I'd laugh at them- you just need to tell her up front that you are so very sorry- you'd really like to help her out but these prices are just to unreasonable for you- best wishes!