Fantasy Costumes has much in the way of sales around the corner and Six Corners. 

November 20th, 21st, 22nd. 20% off all Thanksgiving related costumes and accessories. Turkeys, pilgrims, Indian, hats, etc.

November 23rd and 24th: The entire store will be 20%-50% Off. Some exclusions apply.

November 25th: 25%-50% off all children's costumes, Some exclusions apply. 

Week of November 27th: Pub crawl Santa costume regularly $29.99 will be on Sale for $19.99.

Week of December 4th: 20% off all Christmas related costumes and accessories. Some exclusions apply.
 

More info here.