BuyCostumes.com has 30% off Regularly-Priced Items when you apply coupon code GHOST30 at checkout. Shipping is Free with $65+ purchase or it starts at $7 (economy shipping), or Free 2-Day shipping for those who have ShopRunner.
Coupon can be used for Regular Priced items only, not sale items:
The following are NOT eligible for the coupon code, however are great deals: