I just went to New Jersey for work. There was no time to shop but I did spot a giant Walmart within walking distance of my hotel and found 30 mins to make the journey.
For those unfamiliar, there is nothing more satisfying to a beauty junkie than an American drugstore. They are always huge, they have them everywhere and they sell a vast range of products from biscuits (in a pharmacy, yes) to nail polish to ped eggs (waste of time by the way) to 50,000 types of body lotion. And they are cheap, cheap, cheap. And of course they sell drugs - Tylenol cold and flu, Advil etc all in giant packs of pain relief heaven.
Walmart is, of course, much more than a drugstore but it was all I had available to me so I hot footed there. It's not quite as good as a dedicated drugstore but it provided me with Maybelline Great Lash mascara in a better range of colours than you can get in the UK. Here it's hard to find anything other than blackest black. There I bought some brownish black and soft black. Less than $4 each. And I got a whole load of travel sized toothpastes, cotton buds etc. I got a pack of three Carmex lip salves with SPF 15 which was the princely sum of $2.
Altogether I spent $52 and $25 of that was on a bottle of antihistamines (so much cheaper than over here). I would have bought loads more but I had very limited luggage space as I wasn't checking my luggage in.