Reduce use of HTTPS protocol as much as possible

I’ve noticed that some pages on our site were opened from my home computer with huge delay –more than 30sec, but others- almost instantly.
The problem was with pages that use HTTPS(SSL protocol). It seams that my internet provider had performance problem, but it had huge impact on pages that was opened using SSL.
In the normal development/test environment we never noticed the problem, but it could be a big issue  for users with low bandwidth. 
We need to redesign our application to use https protocol only for a few pages, that work with passwords and credit cards. It also will help with annoying messages: “The page has both secure and un-secure sections”
There are a few related links :