Plato's Closet
Not only used clothing; ours also has new clothes which may have blemishes, are poor sellers, or leftover stock.
KMart & Walmart have Hanes t shirts in 6packs cheap; good for stretching out the life of your overshirts.
If you have hard winters, Vintage Trends has older Military overcoats pretty cheap. The older, the better. The weight of the wool is incredible, and they're sharp.
It's coming, folks. Cotton & fabric prices have just gone up 30%; it has yet to hit the stores. Be prepared.