First it is free to join. Secondly there is a 595$ charge but that is if you want the value package which is for the software previews, etc. You have to have a project plan so it is not a cake walk to join and have the value package. I feel it is well worth the money.
I know where you are coming from. My employer has decided to not invest more money in this technology, but I feel the invest is good for me. I want to stay connected to the platform and when the economy changes I am sure there will be more jobs in this field.
I did look it up and it is called PartnerWorld for Developers.
http://www.developer.ibm.com
Joe