Nitrojeff,

I think it depends on who is writing it for you. You can easily spend a couple thousand dollars a month having someone produce very well researched and written content for you and maybe having a couple different editors.

If you go with a service and not someone specific as a contractor, you may pay less. The amount of content you are ordering will also (obviously) affect the price. I would say if you had a blog and were just buying general content from a service you might spend 50-100 dollars per month for a couple blogs posts per week.

There are some other ideas in this thread,

How much does it cost if I hire a pro writer to write an article? Content, Writing and Copyright forum at WebmasterWorld

Best,

Shawn