The mini cards are fashioned out of sterling silver and cost $200 a piece. They are pre-loaded with $50 so you're basically paying $150 for a silver key chain. The cards each come in a red snap pouch which, in turn, is packaged inside of a red gift box with a bow.
You can find the cards on Wednesday, November 12, 2014 at participating Starbucks stores. It will also be available for purchase online on the brand's online store (limit one per customer; free shipping).
These aren't as exclusive as last year's rose gold cards, which were limited to only 1000 (and sold out in seconds), but if you're set on getting one of these, you'll still need a fair bit of luck as they tend to get snatched up very quickly (partially due to resellers on sites like eBay).