One of my colleagues from the ISV team was talking to me recently about the difficulties many developers face with getting into .NET development. She was talking specifically about developers who have a great idea for a product based on .NET but who can't justify buying an MSDN subscription to get Visual Studio, XP/Vista, Win Server 2003, SQL Server, Biztalk, etc etc.
She went on to tell me about a low cost way of getting around this: Something called Empower. What is it? Quite simply it's heavily discounted MSDN subscription for developers who are building a product for resale (ie what we called Independent Software Vendors or ISVs). It costs about £260 to get onto the programme in the UK, similar levels elsewhere in the world.
The actual deal is slightly more complicated than just an MSDN sub - you get some extra pieces on top, but also have some restrictions - but what it boils down to is a whole truckload of software that you can use to build your app.
Take a look at this link for more details, this is a great offer and I wish more people knew about it. In fact, I wish I'd known about it before I joined Microsoft...