If you do want to get the stuff from Duluth, I'd suggest go on their website & sign up for an account and select that you want their marketing e-mails sent. They are great comedy in their own right. The important thing is, that they very often run 20% or 30% off specials that also include free shipping over $50, so I usually wait for one of those then stock up.
I'm rough on my underwear and was wearing out the budget type in a month or two, usually in my rotation the Duluth stuff lasts at least two years before it has to get replaced.