[callum85]

But the £28 one comes with RAM, CPU, wifi sensor, camera, and it's two thirds of the price. Even if the other screen specs (brightness, viewing angle etc) are really terrible on the £28-tablet and incredible on the raspberry pi display, this still seems very expensive, and the difference seems like more than just an economy of scale thing.

[sangnoir]

I mentioned 3 things that might explain the price difference in my comment, not just economies of scale. I should have been clearer

1. Economies of scale

2. Difference in quality of the display

3. Booking factory capacity in advance (there's likely a huge opportunity cost to the manufacturer)