Maybe you could expand your market by doing other kinds of quick online document design. Instead of resumes, businesses might like to be able to generate attractive proposals, marketing, or fund-raising documents. They would pay more than $9 for such a service too. When I looked at your site, that was the first thing I decided you could possibly help me with.

It seems like you could have a pretty broad offering by replacing the templating functionality of MS Word for various documents. You can compete both on price and ease of use - I think Word ends up being pretty imposing for a lot of people.

You probably should stay out of finance documents though (invoices), which tend to get auto-generated by software. That would require integration effort, as I don't think high-value businesses tend to do invoices by hand.