I've seen about $30 in two weeks from a simple game I have in the Android market. It's not a terrible game, but it's not great either. The free-version reviews are not very good (technical reasons), but some people who bought the paid version left raving reviews.
Like everything else, it's about quality and marketing. Once you leave the "just in" page in the Android market, you vanish. If you want to make this kind of money, I "guess" you better be good enough to be featured, have a 4-5 star rating, and find ways to get noticed (blogging, etc). That being said, I haven't done any of these - so it's all assumption.
As for price, I can attest that for my second game I put out, lowering my price killed sales. The numbers weren't high enough to say what price works or not, but statistically, lowering didn't work. The price was raised from $0.99 to $1.99 again today and I'm waiting for new results.