Costco merinos here, too. I also have an unopened bundle because I cannot wear out the socks from the first two bundles. I'm forcing myself to toss those from the first one (the pattern is different, so I can tell) but they're still almost perfect.
The absolute warmest socks (as well as hats and gloves) I have ever found are by Heat Holders. Can't believe how much warmer they are than anything else.
While we're on the subject of expensive but worth it...once again allow me to trumpet Duluth Trading Co underwear. Two years now on mine, and they are as good as new, even the waistband elastic. Simply indestructible. AND comfortable. I have both Buck Naked and Armachillo styles. I wear the Buck Nakeds most of the time, and the Armachillos for summer golf.
