You might try this product which does not cost:

SQL Server Database Publishing Wizard

For further details on usage please see:

http://www.codeplex.com/Wiki/View.aspx?ProjectName=sqlhost&title=Database%20Publishing%20Wizard

It can be run via command line and schedule through SQL Server's job scheduler.

Biggest issue I found with it is that it does NOT script out users properly. It converts them to roles. However, if you are primarily interested in the schema, it may work for you.