Why are iPhones so cheap to repair?

Apple only charges around $500 to repair the glass. That's less than the cost to replace a car's windshield. How do they repair them so cheaply?

AirPods or new iPhone?

Should I get airpods or save the money towards a new phone? I still have the iPhone 5s lol, and I've been wanting to upgrade for a while, but I really want airpods too.