As I noted before Karol isn't only writing stuff, this is in fact a small part of his job, he is editing/managing our other writers and he get's paid on an hourly basis.
The deal that we have is a bit more complex, but to get an idea we pay >$50 / hour.
There are copy writing services that can write articles for you. The one I am familiar with charges per word, so the cost would depend on the length of the article. If you want higher control that involves in house editors checking everything before it goes to you, you can set up a team. That will tend to cost more.
As I noted before Karol isn't only writing stuff, this is in fact a small part of his job, he is editing/managing our other writers and he get's paid on an hourly basis.
The deal that we have is a bit more complex, but to get an idea we pay >$50 / hour.