Amazon discounts a selection of toddler boys' and toddler girls' boots, with prices starting at $6.36$6.58. Plus, Prime members bag free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping starts around $5.) Note that prices vary by size. Some best bets:
Carter's offers its Carter's Boys' Snap-Up Applique Cotton Romper in Navy or Turquoise for $4.20. Coupon code "DMCAR175" drops it to $3.57. With $6 for shipping, that's the lowest total price we could find by $7. It's available in sizes newborn to 24 months.