Ah, but part of their argument is that it is always worth it so that when it is worth it, that content doesn't stand out. So, by their own argument, they should enable https even for the static content pages.
AES is implemented in hardware now. RSA is cheap to compute; SHA1 is not even a factor. If you want forward secrecy, DON'T use DHE, use ECDHE; plain DHE is expensive.