Warranty will be valid only in US, meaning iPhone would have to
be sent to friend/relative/co-worker in the US to take into Apple
for evaluation and then friend/relative/co-worker will have to ship
the repaired/replaced iPhone back to you (shipping costs, insurance,
import duty, etc. are your responsibility). LTE/4G and other features may
not work. Price listed on website does not include tax. Supply
may still be limited in November.
It is always better to purchase your iPhone where you intend to use
it. Not only will you have compatibility with local wireless providers,
but you will also have a warranty. Warranty on an iPhone from an
EU nation is valid through out the EU.