I went to my Gamestop today to preorder a game and asked the employee there some things including questions concerning Disney Infinity. He told me that when I purchase the game, I can select one free toy (character/figurine) with the purchase. So that basically means buying the game at Gamestop will get you four characters, the other three in the starter pack.
Now I have no clue if this is a limited time thing or not. Or if it's only regional (I'm in Texas, just fyi). But he did not mention pre-ordering it, so I do not think that's the case. He could very well just be wrong, lying (doubt it, though, he was really cool) or misinformed. But in any case I urge you to check out your local Gamestop and ask about this.
And please note that I am not meaning to promote Gamestop or anything, I'm not a bot, lol. Just trying to spread a possible secret.