I found these at BestBuy when I was I looking for an alternative to ear buds for my little ones. What caught my eye was the reviewers comment about a teacher considering adding them to her classroom supply list. I found them at MacMall for $9.99 with free shipping http://www.macmall.com/p/5784594?dpno=7932923&source=zwb12166
"Have you considered", pitching this to some of your teachers? ;-)