The money's what matters? Go into an investment bank (i.e. Goldman Sachs) and start doing stuff. It's easier to move teams internally than get hired for exactly what you want. Demonstrate that you are willing to put in the time and take the risks and you'll get your 100k, for all the good it will do you.

Learning a new language part time is easy - if you're smart you could certainly pick up Ruby or C# in a couple of weekends. You don't need "experience" to get good at something, only to get hired for it. So again, the secret is to get hired for a position that's nominally doing something on your CV (web developer), then transition within the company to doing what you want. If need be, once you have your C#/whatever "experience" from doing it at this company you can then use that to get a job as a "C# developer" at a second company (possibly at higher salary). It's insane that this is how things work, but that's hiring practices for you.