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.
Crocs takes 25% off sitewide during its Presidents' Day Sale. (Discounts apply in-cart.) Shipping adds $4.99, or get free shipping on orders of $24.99 or more. Deal ends February 20. A couple of best bets, with prices in-cart: