Sometimes finding the right make up brush can be a real pain. Often we pay out large sums of money only to find ourselves favouring a particular brush that came with a set or pallet years ago and can never be found again.
Often price is no guarantee of quality.So in my experience it is best just to experiment. Discard the ones that come with large price tags and just blind test. Don’t choose a brush just because it says if was designed for a particular area. Contouring brushes can make good blending brushes and visa versa. And I am not against a good old plain hack with the scissor, if you think you maybe able to save a brush that you never use. Rather that than let it go to waste.
Here is a fabulous article which lists brushes and some dupes worth investigating.
http://makeupobsessed-beauty.blogspot.co.uk/2011/09/affordable-dupes-for-mac-brushes-dupes.html