I worked in the laptop battery pack industry for a few years, your description is fairly accurate. 6 cell packs cost ~$22 to manufacturer. 9 cell packs cost ~$

I worked in the laptop battery pack industry for a few years, your description is fairly accurate. 6 cell packs cost ~$22 to manufacturer. 9 cell packs cost ~$30 to manufacturer (outdated numbers). Yet, 9 cell packs MSRP for easily 50+% more.