I'm ridiculously busy right now, and I don't have the time - sorry. What I will do is point you to the resources I've been using:
http://opencircuitdesign.com is the primary resource, which gives you layout, design, proofing, and setlist generation.
I'm not aiming for anything even remotely state-of-the-art, I'm looking at a 180nm design and even that might be pushing the hobby funds. You can get "shuttle service" at various places to share a wafer, or you can use efabless (link on the magic page above) to do a lot of the work for you, at additional cost.
The guy who for years wrote and maintained Magic (the layout tool) now works for efabless, and he's a great guy - especially if you submit patches to him :)
It's a lot of hard work, you have to worry about all sorts of things you can take for granted in an FPGA (clock routing, i/o bonding and pad designs, oscillators for clock multiplication etc. etc. and yes etc. again). But there's not many people who can say they taught themselves how to make an ASIC :)
And yes, many kudos for teaching yourself how to make an ASIC, that is very cool :-)
I have a long way to go to get there.
I've been out of the open source silicon field for a while but want to get back in. My side project is building a small-scale factory for custom ASICs, rather than getting them made in another factory. It's a very interesting problem, and quite different from ASIC design issues since a lot of it is physics, and obviously there are many factors that are different on a small scale.
The goal is an open source silicon service to the extent of making it relatively affordable for others to iterate and reuse designs, in the hope of developing a thriving scene much like happened with open source software, GNU/Linux etc. But it is proving hard to find the time these days. And as you say, it's expensive, no matter how you go about it, even though affordability is a goal of the final service.
