I can't find any Samsung prices for the M20 screen. There are plenty of off-brand Chinese displays to be found, but none of them seem to have any guarantee of being genuine, original parts.

If you're willing to go for a subpar screen replacement I suppose that's cheaper, but the two products serve completely different markets. A promise to keep a stock of replacement parts comes with higher prices, stripped screens from Chinese recyclers can sell replacement screens for much cheaper as long as supplies last.

I cannot believe the Samsung screen is so cheap. Is it genuine? Is it easy to replace yourself?

Displays are the 2nd (sometimes 1st!) most expensive part of any phone (after mobo) - 75 as a % of the overall cost of the Fairphone is not a high %.

The Galaxy M20 retails at a third of the price of the FP4...