Right now at Walmart you can get George Short-Sleeve Cotton Polo Shirts 4-Pack Value Bundle in 14 Different Colors for $20!
This is great if your kids wear uniforms! The shipping is only $0.97 or FREE with $45 order!
This post is thanks to 
http://savingwithsara.blogspot.com/2012/07/kids-polouniform-shirts-4-for-20-walmart.html
