I was just in my local Costco and grabbed a few of these. In the store they were $12.99, but even online price of $19.99 seems like a good deal. For size reference, I’m 5’8″ and 155 lbs; decided on size L, which gives me a little extra room. They’re nice and lightweight, and should make a good base layer.
https://www.costco.com/seg’ments-ladies’-merino-wool-top.product.100833293.html

