I am going to start submitting articles, and the main reason is obviously Link Juice. However, to post a link in the article... it usually cost around $30+ per link Isn't this considered a paid link??? Can I be penalized for it???
Submitting articles to where? I think paid links never really detected by Google except you buy links from TLA or such service or you sell links from directories. If you sell links manually, Google is not able to detect it (unless until now). THis is my point of view based on my own research (search for competitive keywords then check the websites' back links who rank well in that keyword, etc.). Some websites which only depend on paid links (despite the form of the links are clearly paid ones) still sit on the high SERPs in competitive keywords. It means Google is still far from detecting these forms.
Submitting articles is fine, you just need to be concerned about duplicate content. If you put the same article on 1000 sites, the back links will get ignored. It's good practice to not have the same text on more than lets say 30 or 40 sites. If there is an article submission service that doesnt let you submit at least 1 article for every blog/directory in their submission list, I would avoid that service. Your money is better spent on services that allow many/unlimited articles/versions of articles.