The thing I like about Microsoft is that, if you don't like the licensing deal on rep tells you, you just ask another rep until you hear what you want.  :)

From the Microsoft SQL lIcensing page:

"Processor license. Optimized for customers building business-to-business (B2B), business-to-consumer (B2C), and business-to-employee Web-based applications. A single license is required for each CPU in the operating system instance running SQL Server. This license does not require any device or user client access licenses (CALs)."

The other beauty of SQL and DNN is that you only have a single user accessing SQL, the ASP.NET process account.  So you don't need the external connector for the web server either.  If you're a host, you may want to look at the SLPS licensing.  You only pay for what you use.

Jeff