Sharepoint 2003 is going to cost my company around $19,000. That is for the server license and all the client licenses. The client licenses are $71 each...there is volume licensing available, and that makes larger implementation more "cost effective"
DotNetNuke is free, but doesn't have some all the slick corporate features of SharePoint.
I have no idea how import and this is to you or your company, or how many users you'll have.....my company can afford SharePoint...so they chose to use it for thier Intranet. I would rather have seen DNN get used :)
The main thing that is missing from DotNetNuke that would make it really usefull in a corporate environment is workflow...and that is coming in the future.
you can integrate other CMS's that have workflow into DotNetNuke, such as Ektron CMS. I have spoken to Eltron about this, and they were able to integrate it with IBuySpy, but they didn't not try it with DNN..but I'm sure its possible.
If money were an issue..and you wanted a really robusy Portal, you could rollout DotNetNuke and wrap it around somethying like Ektron CMS and potentially save lots of money.....
Bot MS and Ektron have different licensing requirements, and one can be more expensive than the other depending on your needs....generally, for smaller companies you save with Ektron....but money may not be your only concern
The peopel that run my company have a serious Microsoft hard-on...so they like to stick with MS and generally don't care about the money.