For most cold weather travel needs, I recommend fleece-lined rather than merino wool.  They're much more cost-effective, very warm, still breathe well, and you're usually either layering them under something like wind-proof pants, or you want them to be cute (like with a sweater).  I tested both on an Arctic winter trip and didn't see a big difference.  Only for the most extreme cold weather outdoor trips would I splurge on merino wool.