Costco's gold bars are a popular product, and now the retailer, which also sells silver coins, has added platinum to the lineup. One-ounce platinum coins and platinum bars are only sold online and only to members, and they cost $1,089.99 on Costco's website, Quartz reports. (If you live in Louisiana, Nevada, or Puerto Rico, though, sorry: They can't be delivered there.) While the value of gold has been consistently increasing in recent years, the value of platinum has not held as steady, CNBC reports. The precious metal saw its value increase by more than 15% over the past year, but after passing $1,100 earlier this year, its value has decreased by more than 8%. (More Costco stories.)