Take my particular case, though. I spend 8 hours a day on my computer at work, I spend 5 hours a day on my computer at home (use my car to go to work). I spend 10 minutes a day on my smartphone reading the news or playing 2048, which is usually when I'm in the john, or waiting for someone when I'm on the move. I don't have a use for a laptop, right? It's desktop all the way.
That said, I like reading in bed. And I go on vacation from time to time, and sometime spend more than a couple of hours away from my computer. Those are times when my smartphone just doesn't cut it in terms of digital content. Does it make sense for me to spend more than 500USD on a tablet?
My answer would be yes, but only if I earned like 4000USD a month or more. Which, I'm not, is not that unusual in the states or in the UK or Germany or something.