A question for Doper translators

I used to do freelance translation work from time to time, and I’d like to go back to doing that. I’d like to work at least 20 hours a week on translations.

I’m planning to join the ATA (American Translators Association), since I’ve heard that membership can help you get more business. I’ve also been told that you get better clients (i.e., more knowledgeable, easier to work with) that way.

I’m also thinking of buying memberships at job portals like TranslatorsCafe.com and ProZ.com.

In your experience, are job portals worth the money?

I’d really appreciate any help you could give me.