At Reebok, buy one pair of outlet shoes and get 50% off a second pair of outlet shoes via coupon code "BOGO50". Shipping adds $5, but orders of $49 or more qualify for free shipping. Size availability for some items is limited. A couple of best bets, with prices before discount:
Walmart offers these Toddler Boys' Beach Print Flip-Flops in Blue for $1.86. Opt for in-store pickup to dodge the $5.97 shipping charge. That's a buck off list and the lowest price we could find. They're available in size 7/8 only.