I should also add that I think this is over generalizing. For some of the sites I think it definetly worths the money, for some sites and directories it does not. Depends on what you want to do. If you are going to be 118th in a directory with 150 others in a competitive market, probably not a good idea but for a niche or a small directory for a subdomain subcategory that you are going after a specific term that has commercial value, I will go for it.