At Target, buy any select kids' apparel, pair of shoes, or accessory and get a second of equal or lesser value for 50% off. Shipping starts at $4.99, but orders of $25 or more bag free shipping. (In-store pickup is also available on select items.) Deal ends August 29. A couple of best bets, before the discount:
Walmart offers these Toddler Boys' Skull Print Flip-Flops in Black for $1. Opt for in-store pickup to avoid the $4.97 shipping fee. That's $4 under the best price for a similar pair elsewhere. They're available in sizes 5/6 to 11/12.