What makes some cell phones worth ten times others?

I've tried to use cheaper stuff...just to test if having higher end stuff was worth it...Samsung Tab 4, totally Boggs down and is unresponsive just doing normal surfing. I'll pay a few hundred more for high end equipment...it's actually cheaper if you buy a higher end device and keep it longer. Replacing cheap devices every 6 months or so is not good economy.

Thanks!

Jeremiah