I was in a retro mood recently and actually looked at a flip phone to buy and the cheapest I could find in my country was about the same price as a low-cost Android. So, no buy.
The guys selling under the Nokia brand are also rejuvenating old products but they are going too far: I don't want a Nokia with a color screen, better graphics and an app store for games. I would want precisely a black and white (or e-ink!) display, no external apps whatsoever and no game included by default. There should be no reason to fiddle with a retro phone.