Apple's screen prices are actually fair if you care about getting a "good" one. If you don't (and if you're not using it for color-related work it doesn't really matter) then unofficial screens can be a good deal.

My experience: I replaced my laptop screen thru iFixit and the replacement part had a "soft focus" camera. It also has worse backlight bleed+a little bit less contrast than the official part, and a dead pixel.

They had good customer service and when I complained about the camera and they refunded me some money, but next time I will probably (begrudgingly) pay the Apple tax.