Many people consider buying iPhone in USA and using it elsewhere in the world.
The main driving factor is cost.
Here is some important information you should consider before buying iPhone 5 in USA and use globally.
There are 3 iphone5 models. ATT, Verizon/Sprint and the world model (sold only outside US).
The main difference is in the LTE frequency supported.
See http://www.apple.com/iphone/specs.html "Cellular and Wireless section).
http://appleinsider.com/articles/12/09/12/apple_to_sell_3_variants_of_iphone_5_for_international_lte_coverage
Verizon under contract is selling unlocked iPhone 5.
That means, you can insert nano-sim from any other carrier and start using it.
You will only be restricted by LTE support.
An hidden link at apple site shows $650 for 16GB unlocked version.
http://www.apple.com/search/?q=iphone+5+factory+unlocked
But they are not yet available.
India specific info:
None of them support LTE frequency in India. India is in Band 40.
http://en.wikipedia.org/wiki/List_of_LTE_networks
So you can buy any model above and use it in India on 3G. 3G frequencies on all 3 models are same.
India operators work mainly on 2 frequencies for voice (900 and 1800). For 3G they use 2100
http://www.gsmarena.com/network-bands.php3?sCountry=INDIA
Verizon models are the best bet for international use because they come unlocked.
You can use in India without issue.
ATT and Sprint ones, after purchase, you need to get them unlocked.
