Your question is ambiguous, please clarify the reason why you want to change the tyre and what you expect to achieve. Only then someone can answer correctly. The current question can get replies from people who changed the tyre for exactly the opposite reasons, that would only confuse you.
And whoever answers the question, please also mention how many kilometers you have done on the new tyre(s).
In my experience the wider rear tyre costs much more, because it consumes more fuel and
1) The similarly priced tyre wears off more quickly than standard tyre, or
2) The more expensive tyre does not run as long as it should.
I have seen people changing the rear tyre with a slick sports tyre, I would never attempt to descent from Nathiagali or Thandiani in rain with that tyre.
If you follow the Road Trips forum you might have seen the offroad tyre that lovebikes is using.