Although there is nothing special about it except the gargantuan battery size, the Energizer P18K Pop might prove that many people would pay more than US$500 to get the world's longest-lasting smartphone that has the technical specs of a US$200 mid-ranger otherwise. However, Energizer must hit the US$1,200,000 goal first.
https://www.notebookcheck.net/The-Energizer-P18K-Pop-crowdfunding-campaign-starts-on-Indiegogo-shipments-could-start-in-October.414841.0.html