Travelling to the US in 10 days, where to buy cards?

I'm going to be travelling to Boston and NYC in 10 days and would like to know where I can buy some cards. Preferably Theme Decks, Blisters and Tins (I buy Booster Boxes online) I'd even love to check out an actual card store if there are any close by.

I'm from Australia so even the USA retailer prices will be much more affordable than ours.