All great questions, the merino ones I can handle 😉

Yes, merino is expensive, but it does last if you take care of it. The stuff you get on Amazon is often thinner than it should be, and prone to excesive wear. Usually a merino mix, where the garment is over 50% merino is a good balance, though we go more merino in socks (Darn tough with around 70+% and the lifetime warranties make u for the price to us).

For washing, we either use a bag with a gentle wash cycle or hand wash all our merino undergarments (and others) using Nikwax wool wash. We are in the outdoors a lot, so have definitely learned the advantages of the natural antimicrobial (and thus anti-smell, too) capabilities of the material.

As for itching, while merino is wool, it is from an entirely different kind of sheep than “normal” wool, and has a much tighter weave. If it’s authentic, it should not itch at all. If it does, it’s probably mixed.

And for washing frequency, that’s part of the reason we use merino. May be gross to some, but if you’re backpacking, you end up airing out your undies and socks on alternating days as you hike, and merino is great for that due to the above mentioned antimicrobial properties. (Note: We are not “alternative” in any way to be clear, we are both engineers and there’s science behind it)

For your final question about the gusset, that’s outside of my area of expertise because she and I haven’t discussed that and she’s out ATM, but my guess would be the contact point of the cotton is what natters most, so a cotton gusset would be A+. I’m happy to ask her when she’s back, if you would like.