When will iPhone 5 screen replacements be cheaper?

Not much more to say than that haha

Umm… They are prob only gonna get more expensive. Things never really get cheape. They usually get more expensive as time goes on.

In about 5 years when the iPhone 10's screen will be twice the length of iPhone 5 but crucially maintaining the same width. This way, they can just snap an iPhone 10's screen in half and fix two iPhone 5s.

Hard to say, but not right now.