Don't pay to "join" a site. Those sites are not accurate, up-to-date, or complete. Besides, there's no need to.
Virtually any foreclosure that's for sale is listed on the MLS. (In some cases, lenders will list them on their own websites.) For those listed on the MLS--and, again, that's just about all of them--any Realtor can access that information and provide it to you for free. The specific lender websites are free, too.
Under no circumstances should you pay for foreclosure information.
Hope that helps.