Since Wondercon has forsaken Northern California, the next best thing is Clockwork Alchemy and Fanime. Clockwork Alchemy is the biggest Steampunk convention in Nor Cal (at least that I know of). Fanime is for fans of manga, anime, and cosplayers alike. The tickets are for all. I have yet to go to either, but I have a great costume this year so I want to see who else is interested. Here are the links:
Tickets for all 3 days are $65. I'm not sure what the interest is in a multi-day adventure is, so I'd like to hear from you.