2xAA to D-Size Cell Battery adapter / converter

This is a pretty cheap solution to run the cradle and swing. I can't stomach the fact that I paid $11.5 for 8 D-size batteries.

$2.76 - SoShine 2xAA to D-Size Cell Battery Converter Case (2-Pack) - Batteries: "2xAA to D-Size Cell Battery Converter"