After login, should all pages be https?

Question

This will be a bit difficult to explain but I will try my best.

There is a website that has the login form on every page with username/password fields. These pages a

Answer 1

Apart from the previous answers, since people tend to want to go from HTTPS to HTTP for performance reasons, this article about HTTPS at Google might be of interest. Its main message is:

SSL/TLS is not computationally expensive any more.