I go off how much they value their own products
I bought an iPhone XR from an Apple store for £749 cash. When the iPhone 11 was released, 3 months after this purchase, they offered me £250 as a trade in.
When they enquired about whether I wanted an extended warranty I said no. But then why would I on a product they value at £250? It's the last Apple product I'll buy.
I'd like to say this is sarcasm but it isn't.