Amazon [amazon.com] has 4-Pack Franklin Sports Oversized Foam Baseballs for $8.97. Shipping is free w/ Prime or on $35+.

Dicks's Sporting Goods [dickssportinggoods.com] has 4-Pack Franklin Sports Oversized Foam Baseballs on sale for $8.97. Shipping is free for Score Card Members on orders over $49 (free to join [dickssportinggoods.com]). Otherwise shipping is $8.99.

Details from Dick's Sporting Goods:

• Designed with an ultra-soft construction
• Great for teaching kids baseball
• Made with bright colors so that kids can easily see them coming and hit their mark
• Comes with 2 blue, 1 red, and 1 green oversized 3.5" foam baseballs