This gift set of three sponges from Sephora are the closest thing to a Beauty Blender dupe I've come across yet.

Soft, shaped perfectly, and in three different sizes perfect for every area of your face, these sponges are amazing. They spread foundations, concealers, and powders flawlessly. You're left with a true airbrush finish, just as the name implies.

My only issue with them is that they stain seemingly much faster than the original Beauty Blender, but for the price that's easy to ignore.