Target has price cut tons of Halloween costumes for kids. from Dart Vader to Mermaids, they are about 30% to 80% off depending on the character and size! This appears to be an online deal only right now. Remember to use your RED card and you can save an extra 5% and get free shipping on you picks for Halloween!
They also had some pet costumes in this deal but the quantities seemed to be low so check those out right away!