I haven't been the biggest fan of this game so far (I got it through Kickstarter), but $15-20 is a totally solid price for this if you're a fan of the old Banjo games.
The game plays really well (they definitely nailed the movement and platforming controls), but the levels haven't been as good as BK1 for me (the first level has actually been the best out of the 3-4 I've played so far).