Equal or lower.
Maybe socks aren't included in the sale. Or perhaps their prices aren't changed to $0 until later in the check out process.
But as I previously indicated, I think that this weekend's sale is "Buy 1, Get 3 FREE," on most suits, sport coats, and outerwear. It has nothing to do with socks. So if you tried doing this today, that could be your answer for you.
I'm trying to order these socks: http://www.josbank.com/menswear/shop/Product_11001_10050_100642
It indicates "Buy 1, GET 2 FREE!* Mix'n Match", and my total is $54 even in the payment/send order page.
Anyway, I contacted customer services on the phone and the rep says there seems to be problems with their catalog.