The ZX81 and the ZX Spectrum were interesting machines at the time, but man did they have crappy keyboards.

Perhaps with a decent keyboard, the ZX Spectrum could have stood a chance against the Commodore C64. The price of the ZX Spectrum was 175 £ ($306 at the time) and the Commodore cost $595. Of course, the C64 also had much better gfx and sound capabilities.