Originally Posted by
Schwinnrider
I haven't worn the super expensive rain pants, but any material which will keep water out won't let enough sweat vapor out to keep you dry, in my experience. Rainlegs have the advantage of allowing the backs of your legs to stay cool. I like 'em.
I don't know what counts as 'super expensive' but I've had good experiences with Marmot Precip pants:
http://tinyurl.com/yplsrg
I've worn them through heavy rain and felt slight stickiness at most.
I would also recommend eVent as a good waterproof/breathable fabric.