Hmm, it's probably too late for this, but maybe it's something to keep in mind for next year? I can't really recommend hotel Aida. I've been there before and they had crackheads wandering in and it generally seemed pretty derelict. If you don't mind staying in a roach hotel like that and you want a really cheap one, I'd like to recommend this place:http://www.yelp.com/biz/balmoral-hotel-north-no-2-san-francisco
It's right between Chinatown and the Financial District, with North Beach nearby. It's about a 15 minute walk to the Moscone Center from here, but it's in a relatively safe, clean, and quiet part of downtown. The hotel itself is no-frills; I lived there for over a year and yes, the review on that page is mine (don't let the review scare you, though, it would be a fine place to stay for a week, just not more than a few months) Cactus visited me there last year and he can attest to the small size and somewhat squalid conditions... Although for $150 a week it can't be beat.
They're careful about who they let in, too, so you don't have to worry about crackheads or anything like that. The only crazy people there have been living there for 30+ years and are pretty harmless. Mostly just old people. Call in advance for openings.