Zenon
That sounds like a legal scam to me. Unless they're guaranteeing you a job (within a certain time) once you've signed up, forget it. In the technology world, where agencies are a huge part of recruitment, they collect a finder's fee from the employer AFTER you're employed. If you pay to sign up (or pay after you've found yourself a job, with no help from them), you're paying them for nothing.
Personally, I'd tell them to go play with themselves in the traffic, but that's me.