I don’t know that you need to pay money to get your articles posted. I am putting a list together of sites that allow content submissions for free. Anyone who knows of such sites please respond to this thread and I will compile and share them. So far I have a few in different categories. Submit free SEO articles webseoagent.com , it’s a great way to showcase your knowledge and drive traffic to your site.
Paying to get it done manually = you are assured of the content getting posted in the right categories and depending upon your budget you can even get each article to be unique. Overall it just appears less spammy; higher quality backlinks.