Don't get me wrong, a CS degree is definitely worth it's value because it easily open more doors. You're going to be at a disadvantage on paper compared to a new college graduate with a CS degree because certain assumptions won't be able to be made when recruiters and hiring managers look at your resume, and you may not get a second glance due to them using it as a weeding out factor... this is because on paper many employers equate X years of relevant experience to a 4 year bachelors in CS (where X > 4).
With that said, short-term contract and freelance programming gigs are a dime a dozen, you may still find at first getting an interview difficult. I can't really say for sure though, as I've never been in your position. But since you've stated that you're not exclusively looking for a salaried w/ benefits type gig, and open to doing work with less stability and more risk, I imagine you're going to find that you're most likely not going to be in competition with the bulk of the new college grads with a CS degree, especially not the best of them since they will already have jobs or grad skool plans.
You could try using
rent a coder type services, but IMO you shouldn't waste your time and would be better off finding a shitty non-programming day job to help pay to the bills and instead focus on a portfolio.
I'm not sure where you get your that .NET development isn't free. The free Express Editions of VS are great. These editions lack certain features that the paid editions have, but the missing features are by far "extras" and non-essential to development. The only cost to development is the operating system, and complaining about that is petty because I'm sure if you PM'd me we could figure something out. If you're doing web development and design, I think you're going to make your life easier having multiple platforms to test on anyways. Sure the days of having to support IE6 are increasingly fading. I was just as adverse to Microsoft as you 4+ years ago, however in my opinion their treatment and the tools and ease of development they provide developers is most definitely worthy of praise when I compare it to the likes of Apple. Also, Mono has taken great strides compared to 4-5 years ago, at least in terms of developing multi-platform applications, although I can't speak towards its support for ASP.NET development.
But anyways, I'd say go with Ruby/RoR just because I think you may find it easier to find someone willing to take a chance on you.