The Totsy Blowout sale is still going strong (through 9/8). There are deals for up to 90% off! Shipping at Totsy is FREE on your first order. Otherwise it will run you $7.95 per order (or free on orders of $75 or more).
There are currently kids rain boots on sale for $8 per pair. This is a great deal (I paid $15.99 for my kids boots at Walmart last winter).
These boots are regularly $30, and only have select sizes left. There are some cute styles though, so if they have them in your kids styles then yippee!