No Costco near you? Merino.
any more my feet live in those socks...
bought a pair lord knows how many years ago... and the next year I bought another package of 6 socks...and same the following year.... that last package is like 6 years old... I haven't had to use them yet, as they first two packages of socks, are still going strong and I have no idea how long I've been wearing them now...but I wear them year round anymore...
best value in foot wear under the sun in my book....