Walmart offers Sandra Boynton's Opposites Board Book for $2.93 $3.57. Choose in-store pickup to cut that to $2.61 $3.24 and dodge the $5.99 shipping fee. (Amazon charges the same with free shipping for Prime members.) That's $5 under the lowest shipped price we could find.

Also available is Roger Priddy's Numbers Colors Shapes Board Book for $3.16 $3.39. Opt for in-store pickup to drop the price to $2.81 $3.02 and avoid the $5.99 shipping fee. (Amazon charges the same with free shipping for Prime members.) That's about $3 less than you'd pay in other local stores.