Can I buy unlocked iPhone 5 in USA

Apple has made no announcement about when unlocked

iPhone 5 will be available in the US.

Hello,

is there any announcement yet or even some clue based on historical data when the unlocked version could be available for sale

No, there has not yet been any announcement.

You can find unlocked iphone 5's at any Retail Store. I've just got mine from the store by 5th avenue 3 days ago.

They're saying to be not sure why it wasn't announced yet.

Note that unlocked iPhone 5's will not work on LTE in most other countries, because the LTE bands are not the same everywhere. That's why an iPhone 5 sold in Europe is a different model from the one sold in the US. The phone will still work on GSM, outside of the US, but not on LTE ("4G").

• GSM model A1428*: UMTS/HSPA+/DC-HSDPA (850, 900, 1900, 2100 MHz); GSM/EDGE (850, 900, 1800, 1900 MHz); LTE (Bands 4 and 17)
• CDMA model A1429*: CDMA EV-DO Rev. A and Rev. B (800, 1900, 2100 MHz); UMTS/HSPA+/DC-HSDPA (850, 900, 1900, 2100 MHz); GSM/EDGE (850, 900, 1800, 1900 MHz); LTE (Bands 1, 3, 5, 13, 25)
• GSM model A1429*: UMTS/HSPA+/DC-HSDPA (850, 900, 1900, 2100 MHz); GSM/EDGE (850, 900, 1800, 1900 MHz); LTE (Bands 1, 3, 5)

Here's the list of band allocations: https://en.wikipedia.org/wiki/List_of_LTE_networks

Can you please tell where can I buy factory unlocked iphone 5 in Rochester? And what will be the price of it?

You cannot.

Apple does not sell unlocked iphone 5 in the U.S