Some of those deals are limited-time sales and promotions. But many of the most amazing Costco buys aren't sales; they're everyday essentials. Specifically, they're Kirkland Signature essentials.

Compared to other retailers, Costco's prices may be much lower. Ready to shop? Here are a few amazing Costco buys for under $99. 1. 10-pack of Brita Replacement Water Filters: $32.49 Many people ...