wholesale

I have a friend that wants a simple website where she can sell chocolate suckers. She has quite a few customers already and wants a place that they can order they own product(s). Can someone please give me the a couple of ideas (and point me to how-to's) as to best set it up. Originally we thought a site that people can goto that shows retail prices and they can order product, but when they login (login and password) it could show different pricing. Is this a good way of doing wholesale/retail? If it helps all products would be the same for both retail/wholesale.