Costco really does sell EVERYTHING, including a $400,000 diamond ring that someone just purchased … yep, you read that right! Costco just received a major sales boost after a customer spent almost half a million dollars on Costco bling. Although the warehouse retailer did not confirm exactly which ring was purchased, we’re pretty sure we found the ring, being the only one listed at such a hefty price! Retailing at $419, 999.99, it’s listed online as a “Round Brilli
