The Icelandic discount carrier WOW is starting service from the U.S. in 2015. WOW air

Iceland's WOW air, a budget airline that began operations in 2012, is bringing its service stateside in 2015 -- and announced some crazy cheap introductory fares this week from Boston and Baltimore-Washington to three destinations in Europe: London, Copenhagen and, of course, its home base of Reykjavik, Iceland.

The airline will start service from Boston in March, with five flights a week all year long to Iceland. Its service from Baltimore-Washington International Airport begins in June, with three flights a week, but will run on a seasonal schedule through October.

One-way fares start at $99 (including taxes), but a search of the airline's booking site seems to indicate that it's tough to find a round-trip ticket at the $99 rate. Still, there are good deals to be had: A search for a one-way ticket from BWI to London in June, for example, turned up a fare of $195. Mainline carriers typically cost at least two and a half times that for the same route.

There is a catch, though. WOW air is similar to Spirit Airlines, in that its fares are completely unbundled. So expect to pay extra for everything from checked luggage to seat reservations. If your carry-on bag weighs less than 11 pounds, it's free -- but any heavier and you'll pay for that, too.

So a fare of $195 could easily end up costing $314 if you add one checked bag weighing up to 44 pounds, a seat reservation at the front of the plane, and a carry-on piece that weighs more than 11 pounds. The airline details all its "optional fees and charges" here.

It's not clear how long these rock-bottom introductory fares will last, but to take advantage of them, you do have to book well in advance. WOW says it flies Airbus A320 aircraft, a single-aisle model that's among the most widely used jets in the world.