Spending $55 a year to join Costco (NASDAQ: COST) already represents a bit of a risk as it's easy to make shopping mistakes that make the warehouse club's excellent prices less of an overall value.

Taking the next step and spending $110, a full extra $55, on an Executive Membership seems like an added risk, but it may actually be a safer choice. That sounds counterintuitive, but the more expensive membership comes with a major perk that may actually make it a better deal than the cheaper $55 Gold Star offer.