You might not save in the end but if you want to visit more cities on your way consider this solution with Oneworld carriers. and book British Airways cheap open-jaw flights to New York already for €276! Look for flights departing from Sweden (Stockholm, Gothenburg) and returning to Germany (Hamburg). Remember you can not skip first leg of your outbound flight Sweden - London or Helsinki. Rest of your itinerary would be cancelled. Fare is including all taxes and 23kg checked bag. Depends on the route you choose it may be operated by British Airways, Finnair or American Airlines.
If interested in this promo deal with British Airways you will find plenty of travel options between January and March 2018. Discount is applicable to bookings made by 5th of December or until sold out. Below you can refer to our booking samples..
Booking samples
Stockholm - New York - Hamburg from €276
Gothenburg - New York - Hamburg from €286
Sweden - New York - London - (Hamburg) from £259
If you want to secure your accommodation in USA in advance we recommend service of Agoda or consider following promo codes that offers Booking.com or Hotels.com.
Booking sample of cheap British Airways cheap open-jaw flights to New York from €276 here. In this case you would depart from Stockholm to USA on 5th of March. Your return flight from North America to Hamburg (via London) would be then on 19th of March 2018.