The three here are a Star Trek Into Darkness Klingon Captain (only 1,000 available), Adventure Time Marceline, and a limited edition (only 400 created) Core Series Galaxor2. They've also made unlimited editions of Cartman and Dead Kenny from South Park and Pinkie Pie from My Little Pony. Limited editions in this series are Mysterion from South Park (850), Blake from Workaholics (1,000), Chewbacca (1,000), Ice King from Adventure Time (850), and a variant on their Bruce Lee drive (400). You can also pick up a special edition My Little Pony Fan Favorite Pony (850).
Pricing, of course, depends on how much storage capacity you want. These are available from 8GB through 128GB, with prices ranging from $24.95 US to $129.95 US. The 32GB versions are USB 3.0, while the others are USB 2.0. These are all available for the first time at Comic-Con, but you'll also be able to buy them from other sellers, at least until they run out.