You guys may have picked up on the promo cards Enterplay keeps releasing at specific conventions. Yes, that Rainbow Dash is listed at $300, and yes, she does in fact sell for that and more. It looks like Fluttershy is their third one, and planned for release at Everfree Northwest. Each person is allowed one per badge, so be sure to pick one up at the Enterplay booth!
And in other card related news, Toywiz currently has the official binder up for pre-order as well. Check that out here!