Can a freelancer do this?

Hey

Lets say I have a keyword and wanna hire a freelancer to write content for my niche site. I see some freelancers here can make an article a day etc, but how good is that content?

I mean if I wanna create niche site about: buying used harley davidson.
Then I assume the articles from the freelancer should give good advice on how to buy such motorbikes. Maybe fill in with some history of each model.

And also if users can post comments on the articles on the site, then I assume it won't look good if all the comments is saying that the content isn't good...

You think a freelancer can do this?

of course, you can hire people to do almost anything these days. why not check out Get A Freelancer dot com. You can find some very good writers there for reasonable prices. I usually go for the writers with very good reviews and preferably native English speakers.