The popularity of the ZX Spectrum always feels like a parallel universe to me, since I grew up in the US, and while it was released there (as one of the Timex Sinclair machines that followed their insanely-cheap but also useless $99 Timex Sinclair 1000), it had no traction against the Atari 4/800 and Commodore 64/128. I met people in college for whom this was such a seminal machine growing up, though, and I'm not surprised there's a huge nostalgia market for it.