While some of the cards revealed for Rise of the Floodborn have been heavy hitters including Goofy, Knight for a Day with a whopping 10 defense, 10 attack, and the ability to earn four lore when questing this incarnation of the Cheshire Cat is actually more deadly
Counter target noncreature spell
First off, consider that by starting to proxy, youre essentially making the first move in an arms race. Now, its not that arms races dont exist outside of proxying
Zapdos doesn't quite double up Mewtwo's value, but you can see the major impact that the artwork and each Pokemon's visibility have on the price of the best Pokemon Rumble cards
CD promos are what come to mind for me
You have to accept the risk of drawing multiples, but since up to two is acceptable, I don't think it's much of a problem