Millenials should keep in mind this quote from Milton Friedman: "We economists don't know much, but we do know how to create a shortage. If you want to create a shortage of tomatoes, for example, just pass a law that retailers can't sell tomatoes for more than two cents per pound. Instantly you'll have a tomato shortage. It's the same with oil or gas."
That 400 euro price to repair a laptop might accurately reflect the labour and other costs. Repairing something is much less amenable to automation than mass-producing it in the first place (especially since the latter can be done in a low-cost country).
OP said the replacement screen was 400€ just for the part, not labor. Given the total cost of the computer is 600€ fully assembled that's obviously extortionate pricing for the screen.
That 400 euro price to repair a laptop might accurately reflect the labour and other costs. Repairing something is much less amenable to automation than mass-producing it in the first place (especially since the latter can be done in a low-cost country).