Switching Frameworks in Web Dev

I've been doing Django/Python-based web development for the last seven years, and find myself looking for a job, in a Lower Midwestern city. I've been searching for about 60 days. I'm having some luck but not much.

When I look at a lot of the jobs available either remotely or locally, it seems like the majority are in .NET. I have some .NET experience but it's been a while and was mainly through Windows desktop development.

Looking at the market, it seems like at this stage in my career (mid-senior) it's expected to be more of a specialist in a technology than a jack-of-all-trades. My specialty is Django. However, it has a rather small share of the framework market. If I were more specialized in Java or .NET, I'd probably have more options.

How common is it for people to switch to different technologies and keep in roughly the same salary range? How do you find employers that'd take a chance?