I'm hoping you guys can help shed some light or point me in the proper direction.  My background is front-end web site design (interactive Flash content) and I have been asked to set up a site requiring more back-end work than I've ever done (databases).

With that said, I need to create a site with two key points:  (1) typical e-commerce for users who happen accross the site and (2) registered user login for clients that have been established and receive different rates for specified products in their portfolio.  It is this second point that I need direction with as the registered users will be ordering their products online but the handful of items that they have in their unique portfolio will be priced less than the typical list price -- at a rate that has been set in a contract and will be unique to that client.   When the existing clients log in they need the ability to order from their portfolio as well as from the rest of our inventory-- the rest of the inventory showing list price.

I really hope you are able to follow that. 

Is DNN the best route for me to go?