I'm assuming that all he wants to do is test his site locally before putting it online.
In either case: ASP.NET won't cost you a cent.
.NET framework runtime v1.1 +
.NET v1.1 SDK (documentation, samples, etc)
development IDE:
The WebMatrix project or
Visual Web Developer 2005 Express Edition (part of the Visual Studio.NET family - currently in beta. Not sure it if is free after the final release)
Web server: IIS 5 (comes with XP Pro) will run .NET, WebMatrix also features a builtin webserver for testing purposes
database server:
SQL server 2000 Desktop Engine or
SQL Server 2005 Express Edition (current in beta, final version will be available free of charge still)
To be fair:
Zend Studio is an IDE for PHP and has a free limited feature license available for it.
And just for the record: a full version of Zend Studio will set you back $250, a Visual Studio.NET Standard license can be had for $100.
SQL Server comes with a full GUI and is superior to mySQL which has a command line and rather poor documentation. Free, decent mySQL GUIs don't exist and
SQLyog which is my personal favourite is priced at $49 for a license.
Do the math and see how "free" PHP really is. :shame: