Costco Members: 4-Ct 8-Oz Kirkland Signature Grass-Fed Butter $9 (In-Store Only) Nov 2, 2026 Posted in: SlickDealsTagged in: Costco, deal, extra, off Thumb Score: +22 Costco Wholesale [Warehouse Locator] has for its Members: 4-Count 8-Oz Kirkland Signature Grass-Fed Butter for $10.99 – Extra $2 Instant Savings = $8.99 valid for in-warehouse purchase only.Share this deal:TweetShare on TumblrRedditEmail