I got this free through work somehow and as I usually go for the high end designer mascara I considered it a spare. It has become an item on my main make-up rotation. A cheapy but a goodie.
It has a brush almost exactly like the Chanel one, and is a nice thin formula that holds the lashes up without clumping them all together. A few applications makes it look better and I always use the side of my finger to push my lashes up and get rid of an excess. I think this is the best low-cost mascara - but still desn't match Dior.
Australis - Lash Me Mousse Mascara - Pitch Black