Originally Posted by Pe2k Voices
If you said you bought if off of Ebay or Craig's List, I would say it is a pirated version, but if you bought it on the Amazon market, it is not likely. Merchants who sell their wares on Amazon have to ship their items into Amazon itself for retail, unlike Ebay where you can simply scam people into buying nothing at all.
Actually, they don't have to ship to Amazon unless they're doing "Amazon Fulfillment." I used to sell there, and buy used items frequently. They go directly to the purchaser.
So, it's very likely that the game is in fact pirated. I've bought way too many bootleg items without realizing it, Pokémon games included.