when can i buy unlocked iphone5 in chicago

Apple does not sell an unlocked version at this time.

There are no unlocked iphones sold in the U.S

The GSM side of the Verizon iPhone 5 is unlocked. You will have to pay full price for the iPhone, activate it through Verizon, cancel the Verizon account. You also need to see if the LTE frequency will work where you are located and you need to keep in mind that the warranty is not international and you will have to return to the US for warranty service.

i am pretty sure every major phone company, like verizon, sells unlocked iphone 5's you just have to pay full price of the phone.

wrong. No contract does NOT equate to unlocked.

Reports on the Sprint iPhone have gone either way and I'm not sure if the GSM side is unlocked.

The AT&T iPhone comes locked but if you Restore it as new after authorizing it then you will get the "Congratulations, your iPhone is unlocked message". But again you have to activate it first.

Do you guys know when unlocked iphone 5 will be available in Apple Store??? I will be at the US some days for holidays and I would like to buy one.

No. Apple has not made an announcement, therefore no-one here can possibly know.