Well, it’d take some doing, but it’s possible. The tricky part is that an airship large enough to offer prices that low would necessarily have to carry hundreds of people, and it may be difficult to fill that many cabins for a voyage that long.

Taking the Hindenburg as an example, airships can carry about 1.6 passengers per ton of payload capacity in an overnight configuration. In a modern sense, that surprisingly still holds true for small leisure-oriented airships at modern cruise ship-like passenger densities, because modern expectations demand amenities like extra space, en-suite bathrooms, and showers for each stateroom, which nullifies the gains from having lighter modern materials.

A ship crossing the Atlantic with 100 tons of payload (thus 160 passengers) at a cruising speed of 100 knots would, with sufficient scale and R&D amortization, cost about $4,600 per hour to operate. If we assume a 4,000 nm distance, the standard 50:50 premium/economy split for transatlantic airliners, and Zeppelin’s historical 0.85 ratio of trip speed compared to theoretical straight-line speed with no headwinds or diversions, that would entail a 47 hour flight with an operating cost of $216,000.

Since the average operating costs for medium-sized airlines are about half the actual ticket revenue with taxes and fees and whatnot included, that means 160 passengers splitting up $432,000. If we further assume a fairly standard price ratio of first class paying 5 times as much as coach, that’d entail a second class per-passenger price of $1,080.

That’s not enough to compare to economy for a transatlantic airliner, which is about $300-$500 one-way. In other words, you’d need to either charge first class more than 5x economy (which some airlines do), make extra revenue from onboard restaurants, bars, gambling, and duty-free stores like cruiseferries do, or opt for a bigger airship—and since their payload scales exponentially with linear increases in size and expense, that’s obviously the preferred option. Unfortunately, I don’t have any data or estimates on what larger airships’ hourly operating costs would be. Since there are a few on the drawing board that would be able to carry 2-10 times as much as that, though, it’s certainly compelling enough for some to take interest in the idea, though obviously we’re still years off from getting an airship with a 200-ton payload or more in operation. Something like that would be about as long as the Hindenburg or even larger, depending on the design!