Costco sells a surprising variety of gold and silver – we counted 17 different items

• Costco has made headlines selling gold bars from Swiss and South African refineries.
• Collectors are tracking a dozen or so other gold and silver products the company has sold.

By now most folks have heard that Costco sells a lot of gold.

But while the coverage has focused largely on gold bars from Swiss and South African refineries, the wholesale club's precious metals offering is much bigger.

Due to the speed at which these items sell out and the peculiarities of Costco.com's listings, it can be difficult to find details without knowing exactly what you're looking for. Members must log in to see prices for in-stock, members-only items.

As a workaround, collectors are tracking a dozen or so other gold and silver products the company has sold on a relatively new subreddit, where they bookmark online links and share tips about local warehouses with supply.

Based on spot prices and past comments, the items cost anywhere from a few hundred dollars (for a tube of silver coins) to more than $7,500 (for 100-gram bars of 24-karat gold) — a range of price points that is likely to appeal to experienced and novice investors alike.

While Costco tends to sell gold bars at a very low markup from the market's spot price, coins from the US Mint and Canadian Mint see a slightly higher premium due to their popularity with collectors.

As of Thursday, one-ounce gold American Eagle and American Buffalo coins were available for $2,399 each, while the gold spot price was $2,300.

In addition, a 20-pack of one-ounce silver US Eagle coins was available for $689, and a set of 25 one-ounce silver coins from the Canadian Mint was priced at $809, compared with a silver spot price of $29 per ounce.

Even though Costco doesn't make much profit from its gold business, the company is likely content to keep it up for a few reasons.

Pulling in hundreds of millions of dollars in sales through Costco.com is a relatively easy way for the company to show strong e-commerce revenue growth.

Plus, the items' exclusivity is yet another way to keep existing members happy and attract new sign-ups.