Which is better text links or directory submission? If I buy either of them how can I tell if I got what I paid for?
With buying text links outright, you can use this tool to verify the authenticity of the site's pagerank: http://www.seologs.com/pr-check/pagerank.html With directory submissions, most people providing the service send you a report containing the list of directories after the work is completed. You will also receive confirmation emails from some directories when your link is submitted to them.
I always prefer a link from relevant pages as valuable. Therefore, text links from a content page is far more natural than from the directories.