With orders of $25 or more, Amazon offers the Trademark Poker 24K Gold Foil Playing Cards for $4.98 with free shipping. That's the lowest price we could find by a buck. They feature certified 99.9% pure 24K gold foil and a $100 bill print on the back.

Note: This is part of the Amazon "add-on" program and can only be purchased with orders of $25 or more.