Is paying a company $300/mo for SEO worth it?

I am working for company that currently uses Real Search Listings (a href="http://www.realsearchlistings.com/index.html)" rel="nofollow"http://www.realsearchlistings.com/index.…/a as their SEO solution. I have been asked to find out whether or not this is worthwhile as they are paying RSL $300/mo. It seems to me that all this company does is add and edit keywords. Now, I have looked into the SEO Studio software and figured I could do the same things myself as the company is paying RSL $300/mo for. So, has anyone used Real search Listings before? Is it worth paying a company $300/mo for SEO? Do they do things I could easily do myself? What about SEO Studio? Has anyone ever used that and had good results? Direction would really be appreciated.