I work with .NET technology stack for about 4 years.
I am learning and enjoy working with ASP MVC framework and I never did anything serious in other languages.
This is not the question like what is better (I read all similar questions).
What interest me is the cost of switching.
For example:

If you are about to start a start-up company today and you are in my situation not too much money, some good idea that you think others will use and have a knowledge of .NET. In my head I have a few questions that I can't answer and I know that somebody with experience can:

1) Java & .NET hosting. Suppose shared hosting is not good enough anymore, your site has grown and you need more resources. How much Java services is cheaper compared to .NET?

2) I didn't follow hype about ORACLE will kill java long time. Does oracle show interest in investing in java. I mean is is safe to bet on java as a technology when starting start-up (basically did oracle show some will to destroy java platform)?

3) I am not sure what I am asking here. When you use Java you can use JEEE stack or Java with third party stack (spring, hibernate, maven etc.). I saw a lot of project that work with second option if web application is not enterprise level but social networking site for example which stack is best pick?

Summary of this question is is it safe to jump in to Java learn it and build product based on it. It's not too hard for me to learn it. But how much can I get from it.