Hey I'm doing the same trip next month, a week in chicago and 10 days in new york. when are you thinking of going? i havent done much research on chicago, ive heard the museums are really good and the john hancock building. its hard to find any tourist info on the place.
we got our accommodation on sale for about 85 US a night, which was really good. cant remember how much our new york accom was but it was also quite cheap considering its new york and we're staying 2 blocks from central park, 4 blocks from times square.
for new york - dylans candy store (the biggest in teh world) and the 6th ave markets on saturdays are on our to do list as well as the usual touristy stuff. there are some really good packages taht you can get that let you choose different things to do for a set price and you can save a reasonable amount of money eg the nyc explorer pass lets you choose 3 tours/attractions for $140 and its stuff like cruises around manhattan or the ripleys believe it or not tour and stuff.
the woodbury commons outlets just outside chicago i think it is are supposed to be amazing if youre into designer shopping...uber cheap prada outlets etc. theres 500 stores there i think. there are also packages like the ny city pass that get you into all the normal tourist places (statue of liberty, ellis island, empire state building, guggenheim museum, museum of natural history, museum of modern art, metro museum of art) and you can use it anytime within 9 days for $122 which means that you dont have to line up to buy tickets and stuff. if you ahvent booked accommodation its worth going to a travel agent because they will be able to find stuff thats on sale a lot easier than you can on the internet. does that help? ive done a reasonable amount of planning for our trip so let me know if you hvae any more questions.