Where does it say that the a la carte members will not be able to use the forums?  I don't see that in the e-mail I got about the new membership options.

It is in the FAQ that details more about the membership structures.

Can I participate in Discussion Forums without enrolling in annual membership?

• No. A la Carte members will not be able to Post in Discussion Forums.

Here's a link to the FAQ: http://www.paperbackswap.com/help/help_item.php?id=693

A la carte members will be able to read but not post (the exception being the private Standard & Limited membership boards). So, I would guess that they could still read the Bazaar and PM people to request WL multiples, deals, or fulfill selling credits to those that ask for them just wouldn't be able to post within the thread to say they are PMing or requesting.

Hope that helps a bit.

http://www.paperbackswap.com/help/help_item.php?id=693