There are a number of different ecommerce modules available for DNN - some are free while others come at a cost. 

FREE:

The dnn core includes a generic shopping cart module.
NBStore is a free shopping cart with source code available - that has been expanding its functionality  on a regular basis.

PAID
Smith Cart is probably the most full featured cart for DNN - very functional with good gateway and shipping provider support- but possibly the most expensive.
Catalook is prettycustomisable  - BUT - it can be incredibly klunky to drive - and has some seriously dumb workflow methodologies in a few areas.  Possibly its main failing is trying to be all things to all people - that is - it can do a lot of different things from - simple cart, to full blown multi portal / multi vendor or even rental management for hotels and motels - but this diversity makes it a nightmare to drive at times.

There are also a few other variations on the theme - for paid modules take a look at www.snowcovered.com - and search ecommerce or cart.

Westa

Hi Anita,
Well before completing my MCPD I was developing websites using open source CMS such as Joomla! and Dropal. I guess Im looking for the flexability I had in these Systems.
Cheers

Hi Mkariti,
yes, DNN is really flexible, I have no experiences with Joomla or Dropal, the easiest way to find out if DNN fits for your needs - just try it .
Kind Regards, Anita