Joinus2010 via eBay offers this Men's Boonie Hat in Gray/Blue for $2.38 with free shipping. That's a buck below our mention from two weeks ago of another color and the lowest total price we've seen. (Outside of other eBay sellers, it's the best deal now by $4.) It's available in one size fits all.
Note: This item ships from mainland China and may take three to eight weeks for delivery