I've been looking through these and there a number of manufacturers.
I've found some on sale for around $35, but...
Apparently, Icebreaker has several brands that they sell merino wool under, including Red Ram, and the quality seems to vary between the brands.
Reviews of Terramar had a lot of complaints of tears the first or second time wearing them.
One brand had a pair with no fly in it...
Besides those, there is Kuiu, Smartwool, Patagonia, etc, etc.
Obviously I expect to be wearing mine for several days and I'm only looking to get 2 or 3 pairs for now, so I'll gladly pay more if the comfort and reliability justify it.
So, I'm curious about whether particular brands seem to hold up better than others, have better little things, like the waist band, etc.