Original Penguin cuts a selection of its Original Penguin men's polo shirts to $19.99 via coupon code "POLOEVENT". Shipping adds $7, but orders of $99 or more bag free shipping. Deal ends February 20. A couple of best bets, with prices after coupon and $7 for shipping:
Walmart offers the Hanes Women's Long Sleeve V-Neck T-Shirt in six colors (White pictured) for $3.50. Choose in-store pickup to dodge the $5.97 shipping fee. That's the lowest price we could find by a buck. They come in sizes S to XXL, although not in all size/color combinations.