These kits retail for $99 US on the Sigma website, which is the same price of the 12 piece in the brush roll. I prefer the brush holder that comes with this because it's super handy.
purple (Make Me Crazy) kit because purple is one of my favourite colours. I was going to get the black, but thought why get more black brushes? This way it adds a pop of colour to my brush collection.
Edit: The purple one continues to bleed dye as I wash it and is still quite stinky, I think with continued exposure to air it this should dissipate and the dye will stop.
In conclusion, I see no real differences with these purple "Make Me Crazy" kit brushes except for the brush lengths themselves, only a few brushes were the same length, they seem to be all over the place. Not a big deal, but I am very critical of makeup products and I will point these discrepancies out. I know Sigma brushes are factory made so there probably isn't so much focus on quality control regarding size of handles. Also, the black ones overall feel heavier, that is probably because the ferrule on those is more of a metal, whereas the purple ones are aluminum looking. The ferrule is more pinched looking on the black ones too. I think these brushes are nice to have if you don't already have the 12 piece kit, or you want the brush holder.
Disclaimer: Products were sent from Sigma Makeup for review consideration.
Any comments or questions, please ask away!