We're working on Halloween costume ideas in our household. Looking at these links bring some inspiration.
Frisco Kids' classic Halloween costumes on the cheap
Groupon has an onlline deal today and tomorrow, $30 in credit for $15. It's at Halloween Mart and it's an online deal. I saw it on the San Jose page.
If you're new to Groupon, get the deal here.
If you're already a Groupon member, get the deal here.
Red Tricycle has a list of local costume stores (that include thrift and consignment stores).
Halloween deals and coupons online - by Bargain Babe. Some of the discounts might be gone by the time this posts, but many are still good.