A company shouldn't be afraid to contract a tech writer through an agency or marketing company.

You say in the article $80/hr works out to $177K or so a year - in my experience that's not really a proper measure of determing the value of outsourcing through an agency.

In my own company's case - we have a pool of technical writers/documentation specialist that are complemented by our project management and development teams.

So when you contract a company like ours for technical documentation you're getting a whole team and all the support that goes with that.