Probably that you don't need the Database part of the VST-Database Pro
because it's mainly tools for helping you in designing and deploying a
backend database but nothing you can do without it. The VST-Database Pro is
mainly for people working in a team environment for a big corporation.
If you want to develop a .NET application, the Standard and the Professional
versions of Visual Studio - the ones without the MSDN subscription - should
be more than sufficient to develop any good .NET application against a
SQL-Server and will cost you a lot less than any version of Visual Studio
Team. There are also the Express versions than can help you in starting
with .NET without coughing out money.
The Visual Studio Pro can also be bought with either a MSDN Premium or
Professional Subscription. The price is much higher but it might be worth
it for you.
http://msdn2.microsoft.com/en-us/vstudio/aa700921.aspx
http://msdn2.microsoft.com/en-us/vstudio/aa718657.aspx
Prices at:
http://msdn2.microsoft.com/en-us/vstudio/aa700832.aspx