Under Armour Men’s Mystery T-Shirt 5-Pack $40 The links in the post below may be affiliate links. Read the Full DisclosureOctober 7, 2019 by Kim Julian This Under Armour Men’s Mystery T-Shirt 5-Pack is on sale for $40 with the coupon code: UAMEN at checkout. Sizes S – 2XL are currently available. Shipping is free with your $50 purchase.