well done good maths, and further 21/31 = .60$ a day, for 4 hours wireless free, noise cancelling headpones ? is that still a lot ? than why not spending some time on eBay buying some jaybird or samsung BUDS JEEZUS KRIST when you will stop complaining all about the price ???????
Or maybe we could not buy them until Apple figures out a way to easily screw in new battery replacements...