I got 100% merino wool long johns from Stanfields factory outlet for $35 a year or two ago. $20 each for top and bottoms but opted for the trap door model. Some said 100% wool and others said 100% merino wool but they didn't look or feel any different. They weigh in at 16oz for XL. I would guess separate tops and bottoms are about 9oz top and 7oz bottoms. Great skin layer or emergency layer for midwinter. I'm not sure if they still make them but they might still have some at their factory outlet in Truro.

http://www.stanfields.com/products.asp