Last week, Norwegian Air Shuttle launched non-stop service between New York and London, as the first budget airline to fly the route since Laker Airways in 1977. And it's not a huge surprise -- the low-cost market is the fastest growing airline sector, with other budget carriers rumored to be keen on grabbing a piece of the transatlantic market, too. This is partly due to the emergence of more fuel efficient, economically viable, long-range aircrafts. Norwegian's new long-haul routes to the U.S., for example, will run on the airline’s new 787-8 Dreamliner.

But the all-important question remains: How competitive will travel costs on these budget carriers' transatlantic services be?

Norwegian's website is promoting fares that start at $256 one-way from New York JFK to London Gatwick. While we couldn't find a fare quite this low for the rest of the year, we did find a January 2015 one-way fare of $248.20 and round-trip fare returning the same month of $562. For the rest of this year, lowest priced round-trip fares we found are: $1,110 for August; $762 in September and October; $712 in November; and $662 in December.

To judge how Norwegian's fares stack up against other non-stop services, we checked British Airways' fares from August through January. We found one-way rates starting from $496. For a round trip, the total comes to $1,046 in August; $992 in September and October; $922 in November and December; and $1,022 in January. On Virgin Atlantic, the lowest one-way flight we found for this year is $359 in November. The airline's best round-trip fares are: $999.50 in August; $992.50 in September; $992 in October and November; $942 in December; and $1,022 in January.

So August aside, Norwegian's airfares are indeed significantly lower than those of the big carriers. But, as we've come to expect, a budget airline means budget-style service -- and that can have big implications for overall cost.

If you want to check a bag with Norwegian, it'll cost you an extra $43 each way. Reserving a seat will cost another $43 each way, and a pre-ordered menu of two meals and a beer or wine will cost another $48. Smaller snacks cost from $4 for a chocolate bar to $11 for a small sandwich. Finally, you'll also need to pay to use the airline’s headsets ($4) and blankets ($5).

All those extras potentially add up to another $277 on top of the advertised round-trip fare -- or a total of $1,039 in September compared to $992 with either British Airways or Virgin Atlantic (who offer one free checked bag; free seat selection within 24 hours of departure, two free meals, and unlimited beer, wine, or spirits). Assuming that you need the extras, it's only in January that Norwegian offers a significant saving on the entire flight experience.

So if you're happy to travel with only a carry-on and an empty stomach, you won't find a better deal than Norwegian. Otherwise, it might be better to stick with the "frills" airlines over the "no frills" option.

Update: As commenter, James points out, if, at time of booking, you choose the "Add Plus" option, you get two meals, one checked bag, and a seat reservation for a discounted rate of $59 each way ($118 round-trip).

Find The Best Cruises
Find a cruise

Find the best deals!

Click on multiple sites to get the lowest prices

Click on multiple sites to get the lowest prices

Take Our Survey!

We want to deliver more of what you want, the deals you love, and stories that inspire you. It will only take a few minutes.