$500 USD is an absurd price for a "Phone" with such limited usability. Unless you're some edge-case who absolutely "Needs" the longer battery life, I really fail to see how this can justify a $200-$300 price premium over a low end Android phone.
I don't own this phone, but I paid $500 for a Boox Note Air 2, which is an eink tablet that I use for notetaking and reading and replaced my ipad with it. The limited usability of these devices is a selling point, not a downside. But just because I want a device that does less doesn't mean that I want a device that feels cheap. I still want something sleek, well built and snappy. And eink screens aren't particularly cheap either. So $500 it is.