Via Boing Boing, here’s a survey of science-fiction writers on their income:
The typical advance for a first novel is $5000. The typical advance for later novels, after a typical number of 5-7 years and 5-7 books is $12,500. Having an agent at any point increases your advance. There is some slight correlation between number of books and number of years spent writing as represented in the 5-12.5 thousand dollar advance shift of an average of 5-7 years.
As I understand it, 5000 books is a typical first print run for all but the most popular novelists. I was recently talking to somebody who worked at a largish Canadian publisher. She reminded me that, to have a ‘best seller’ in Canada, you have to sell 5000 books. Just 5000! It seems to me that the publishing industry gets far too much attention for numbers like those. I know the long tail applies, but it was a reminder of how few novelists really profit from their work.
DarrenBarefoot.com 
Just proof that you don’t do anything in the book industry if your goal is to have lots and lots of money.
When I was working for the government, I worked with a guy who’d written three books. Two of them sold about 300 copies each. The third was a Canadian best-seller with 3000 copies — and that was a non-fiction book about Morningside or some other popular CBC Radio show (I forget which one). He said he made about $8,000 from the CBC book.
In comparison, a friend of mine sold a romance novel to Silhouette for $100,000.
I noticed you mentioned “Just 5000”. That’s a lot in Canada. 🙂
Your title reminded me of this.
Ah, reality awakens and shucks off its pajamas – another day, another dollar. “No one ever explains to you the economic realities of being a writer as you’re training to be a writer,” I have said for the past two years in my presentation to the Masters of Publishing students at SFU. And I mean it.
Case study: a Canadian bestseller sells 5,000 copies. The author receives a royaltly of 10 percent, or between $2 and $4 (if the price point is $20 or $40, about where most price points are for softcover and hardcovers, respectively). Therefore gross income from a book is $10,000 to $20,000. This is, of course, before taxes. Most books take a few years. Most books are not bestsellers. Most books are lucky to sell 2,000 copies.
Key takeaway: an author cannot make a living from their writing in Canada without supplementing it with: (1) teaching work, (2) freelance writing, (3) a Day Job, (4) grants, such as those from the Canada Council. Writers who do make a living from their writing in Canada do so because they are able to sell foreign rights, particularly U.S. rights and U.K. rights.