Ebay is your best bet - the datacards are all limited run when they're released so they're now out of production.
You don't actually need them, the rulebook and codex combine to give you everything you need to know, but I understand why you'd want the cards (I do too!)
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Tan? You're joking, I'm a gamer, you're lucky I'm wearing deodorant!
My Blog - The Burning Eye Blog (check it out - comments always welcome)
My Project Log - Visions of the Burning Eye
My Gaming Log - Chronicles of the Burning Eye
My Club - MAD Wargaming
My Fluff - Kabal of the Burning Eye, Cult of the Shadowed Blade and Coven of Distorted Perfection