I bought the PW 3G as I was under the erroneous impression that it included the worldwide browser of the K3. Now, that's a feature that would have been worth the $60, but as long as it's just for the Amazon store (and Wikipedia) I don't think so.
(I live 4km from a border, and frequently find myself abroad. Using roaming on my phone it would costs a fortune to check email, so the free 3G would have been great. (Even though the interface is very painful, it would have been a lifesaver in many occasions.) )