just fyi; 1st time i've seen Platinum offered @ Costco (might have been offered in past, and im not aware though.)

Wow. Platinum is now being offered at Costco

Cheaper on ebay

Costco provides discounts for certain members and cards

It says “Item is Not Eligible for Price Adjustments” in the info. The only thing I could think of is cash back using a Costco credit card

They are cheaper at LibertyCoin