$3/1 Similac coupon, hit your back button for a second print.
Also don't forget the Coupons.com $3/1 Similac coupon has reset so even if you printed it last month you should be able to print 2 per computer again.
Use these coupons on the ready made formula at Target or Walmart to buy it for under a dollar. I've also heard that Babies R Us currently has the ready made formula for under $3 making it free with this coupon. I haven't been able to verify that price myself though. Please leave a comment if you have any information of the price of the ready made at Babies R Us.