Be careful when you sign up. I would highly recommend the Pro Product to promote yourself and your own listings.
As far as purchasing buyer or seller leads, the minimum is a 6 month contract and they will NOT let you out of it no matter what. The leads they provide are OK at best but what makes it difficult is they sell the leads to at least 3 Realtors at a time so the potential client is bombarded with emails, phone calls, and sometimes visits to the home. This approach causes the potential client to become understandably hostile. If your OK with that then you will get a number of potential leads.