You brought it up, yvanleterrible ....
Either way, as someone said before, 300 charges at 3 weeks between charges brings me to ... something over 17 years of use on the original battery before I only start getting, what? Only
two weeks per charge? Anyway, in 17 years, someone will be third-partying the battery, or it'll have been replaced with something better. Or more likely, a much advanced reader will have come along, and the PRS-500 will be another member of my personal Gadget Archive, next to my Pilot 5000. And after 17 years of use, it'll be hard to argue that it wasn't worth the investment.