Hi,
Before I comment, let me state my experience so you get an idea of my background and my biases.
I sell sync licenses to music that i write. Essentially, instead of trying to sell music that I've already written, I'm paid to write new music, and then I hand over a sync license or negotiate a %.
My recommendation would be to buy a domain name ($12), use something like blogger, and then soundcloud as your portfolio. Yes, flash stores are very nice and fancy, but they're impersonal. Use a simple website.
To start with $200, I would say you're better off buying a video camera and getting an agent. Use social media as your promotion, just create a little hype around you and have fun.
I wouldn't recommend spending money advertising, or promotion. It's not good for a producer's image in my opinion.
It also depends where you live. I live in Los Angeles, where the agent/social media/sync rights works out.