Some tiles can be hundreds per sqm though.
I believe there is a difference in quality between cheaper quartz based on what I have seen for example the compac quartz has a better colour (darker black) from what I have seen compared to the Starlight quartz and the starlight quartz must be sealed. So I would imagine that the production process is not the same.
I do believe however that without both tiles in your hand you would be unlikely to think there was any real difference in appearance.