Sears offers the LEGO Boy's Ninjago Pajama Shirt and Pants in Blue for $9.99. Opt for in-store pickup to dodge the $5.75 shipping fee. That's $22 off list and the lowest price we could find. It's available in sizes 4 and 6.
Of note, Shop Your Way Rewards members will earn a Sears credit with this purchase and may be eligible for additional credits and discounts.