Cheapest place to get decent quality socks?

I know that this isn't the normal kind of thing to post here, but I volunteer with a homeless outreach club at my school distributing supplies to various homeless camps around my city. One of our biggest requests and biggest expenses is always socks. Since the people we help are outdoors all the time, having thicker/higher quality socks really makes a huge difference. Has anyone found any good source for cheap, well padded socks?

They don't have to be anything fancy, cotton is fine, but just need to be a little thicker/more padded than the ones that are popular nowadays, and need to be crew cut rather than ankle. Costco always has some at $12 for 8 pairs, but if anyone knows of any that are cheaper it'd be super helpful!

Thanks in advance.