I started out doing 1000 word articles for one gig (I get $4).
I got some good review and then TONS of orders, so I drop it down to 500 word articles for one gig. Still, more orders than I can handle.
I'm now at 300 word articles for 1 gig on fiverr which I really use mostly to make contact with potential clients who I then write for off of that site (shhhh).
Off the site I'm making $5 for a 200 word article or $8.50 for a 300 word article for my two main clients.
I'm a native English speaking/writing person but my articles are not well researched or anything. I just kind of write off the top of my head for 90% of them and if I don't know anything about a specific topic I just look on wikipedia and read for 20 seconds before I start writing.
So anyway, about how much do the real "pro writers" make per article? I'm trying to find out what the limit will be for me since I keep offering less words for more money and people keep buying them!