I am writing an application in Asp.Net and I need to decide on a back-end technology.  This will be something I am out of pocket on, and although I own Windows Server 2003 (which gives me IIS/.NET and Share Point services which I need), I am not so enthusiastic about SQL Server's price tag ($6,000 per proc).

The application will be web based, and will contain a workflow engine and a document control engine (with full audit trail and versioning).

The three questions I have are:

1.  Are SQL Server's XML features worth it, considering I am using XML heavily in my application?  I know that I need to see just exactly what is offered in this realm, but if anyone has a thumbs up/down I'd love to hear it.
2.  Are there any other features of SQL Server that make it an obvious choice?
3.  Will a connection to a non-MS server create the need for a bunch of manual coding rather than the nifty way you can just drop a datagrid control (for example) on a page and have it "just work"?

I have looked at Ruby on Rails, Zope, etc., but have decided that the business logic will indeed be in .NET.

While I generally try to use products like MySql and PHP for what I do, based on what you've said, it sounds like the MS product is the best path - then again, I am not a DBA, rather a SysAdmin.  

I've seen some insane apps using .net run on MS servers with the SQL backend.  Most of the developers that I support swear by it.  

you got IM

Thanks for the heads up, "theDave1164".

Looks like the framework and SQL Server are so intertwined that you lose much functionality when you use a different database.

No worries though - my biggest grip was my own license, and I was going to get an MSDN subscription until you told me about the action pack.

At the price this software will sell at, the clients won't care about the $6,000 SQL server license anyway.