Dang how long you need them to last? I started wearing smartwool socks 8 years ago bought 5 sets. And just recently (couple months) started wearing some new sets. I still wear the old ones to on occasion. There thin but no holes.
I got pretty close to one year before the holes started. They would also get stinkey after a couple days and lose the loft. I do like the PHDs for daily use, but they are a bit hot.
I did a comparo on the bridgedales from sierra trading (which are seconds if you look real hard) and factory firsts. The seconds lasted about one year, the firsts did three years. When I spoke to the importer she mentioned that they have a three year guarantee. These were the "light hikers".
Bridgedale stopped making what I thought was the best light-duty sock in the world, the Ventum. This was an asymetrical sock, good padding on toes, heels and top of foot with thin, very breathable coolmax on arch, sides and upper. They said they stopped because REI started copying them and they were cheaper.
Everybody has different feet, and more importantly, different needs. An office worker can use a junk sock and think its great. I have a friend that used to run every day, several miles, with nothing but cheap walmart socks. He didnt care (but is very frugal) and I guess his feet didnt either. But then again, he just got a hip replaced. Most of my use was in hot to very hot climates, desert/mountainous terrain with gear, off trails.