In reply to existing debt:
I saw some for 15 pounds in Decathlon, the only thing against merino is how you can start to cool off after exercise because of the moisture being held onto by the wool.
I read that in high altitude mountaineering merino isn't great and synthetic is much better, in that you smell but don't die I suppose.
The Howies Waffle mid layer with a zip is great at transporting the moisture from the wool base layer outwards though, as soon as you stop the Waffle layer seems to start transporting the moisture, so you're only cooler for a fairly short time.
If you're thinking of wearing merino for Scottish winter climbing or something where you don't want to get cold, it could be worth experimenting a bit.
Cheers
Tim