For some it’s the dream: a flight pass around Europe and the Mediterranean.

For others, of course, it’s an ecological nightmare.

Wizz Air’s new All You Can Fly pass will allow unlimited flights for pass holders for a year, starting September 25, for as little as 499 euros (US$549).

That’s the price if bought today before midnight in Hungary, where the airline is based. After that, the price goes up to 599 euros (US$660).

If the price sounds too good to be true, that’s because, for many people, it will be. For some, however, it’ll be just the ticket – literally.

Flights can only be booked within 72 hours of travel, so it’s best for frequent flyers who can move at the last minute. And they can only be booked as one-way fares – meaning that most people will have to book an outbound flight without knowing when exactly it will be possible to return.

It’s not really possible to book one leg and cancel if another doesn’t appear, either – cancel three times and your pass will be canceled.

The pass is also set to renew automatically – so you’ll need to cancel it if you don’t want to continue.

So what do you get? Unlimited flights – up to three in a day – for the year. For each you’ll pay a flat fee of 9.99 euros (US$11) per segment.

This is the bare-bones ticket – if you want to add luggage, seating assignments, or priority boarding (which allows you a roll-on carry-on bag) you will have to pay extra. Bags routinely cost around 50 euros per segment.

The pass covers the whole Wizz Air network, which covers much of Europe, the Mediterranean and even the Middle East. Only domestic flights within Italy are not covered.

Members must supply a preferred departure airport, from which most of your flights are likely to leave. Most of these have already sold out, with departures from mainly central eastern Europe and Norway left. Not all flights need to leave from these airports, but the airline reserves the right to cancel the pass of those it has reason to think have signed up as being from one area, but are actually from another.

The airline also isn’t guaranteeing a ride on any plane with an available seat. Its terms and conditions are rather opaque on availability, saying that “the provision of flight tickets depends on a number of internal and external factors” including the seat capacity, number of passengers on the flight, and the number of total registered All You Can Fly members – currently set at a maximum of 10,000.

The airline was not able to explain at which load level the seats are allowed or disallowed to CNN.

So is it worth it? Possibly, if you’re prepared to fly at little notice and be flexible about a return. Also, if you travel light. Most importantly, if you’re a solo traveller – even if two of you buy passes, there’s no guarantee you’ll both get space on a flight.

But you’d also need to be a frequent flyer to make it worthwhile. One frequent Wizz flyer, who regularly flies between the U.K. and Italy, said that they usually pay around 50 euros for a basic one-way ticket, booked a couple of weeks in advance.

In June, Wizz was named the worst airline for U.K. flight delays for the third year in a row.

And although its fleet of new Airbuses makes it one of the youngest and most fuel-efficient fleets around, the rapid expansion of budget airlines is one of the main drivers of aviation’s dismal environmental record, according to lobbying group Transport & Environment.