What makes some cell phones worth ten times others?

You can compare the specs, you know...
Side by side comparison.

The display is usually the most expensive part of the phone. The cheaper phones have cheaper displays.

But you asked a "value" question.
Only the customer can make that choice.

With a family of 5, we've had expensive iPhones and Androids and cheap ones. I'm still on my Samsung Galaxy S5. The expensive phones do seem harder to break - dropping the cheaper ones usually breaks them.