As one of its daily deals, Amazon offers Prime members the Calvin Klein Women's Liquid Lounge V-Neck Nightshirt in Black, Gray Heather, or Coastal for $25. Coupon code "30BLACKFRI" cuts it to $17.50. With free shipping, that's the lowest total price we could find by $18. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping costs $5.48.) It's available in sizes S to XL, although not in all size/color combinations. Deal ends today.