It depends on the brand. Similac coupons are kind of rare. If you want
some, I still have 9x $2 off (exp 7/14) left: http://www.mitbbs.com/article0/PennySaver/32471293_0.html
It can be combined with formula check to save a bit more.
If you haven't registered for formula checks, you can go to NextGeneration
board and read the post of how to do that. :)