Barcelona to Morocco for under €25: how the cheap days actually work
There is a Ryanair flight, FR3185, that goes from Barcelona to Rabat for €17 on the right day. Seventeen euros, for an international flight to another continent. On the wrong day, the same flight number, same aircraft type, same month, costs €70. Nothing about the product changes. Only the day does.
I've watched people react to this two ways. Some assume the €17 is a trick — hidden fees, phantom fare, won't really be there at checkout. Others assume the €70 is the scam. Neither is right, and understanding what actually drives the gap is the most practically useful thing I know about short-haul pricing.
Buckets, not prices
Low-cost carriers don't really have "a price" for a flight. They have a ladder of fare buckets — maybe 20 seats at €17, 30 at €25, 40 at €40, and so on up. Every booking climbs the ladder one rung. A flight's displayed price is just the cheapest bucket that still has seats, which is why prices only ever ratchet upward as a specific departure fills, and why two dates a day apart can sit on completely different rungs.
The cheap days on Barcelona to Rabat are cheap because demand is thin enough that the €17 and €23 buckets never sell out. And demand is thin on entirely predictable days: Tuesdays, Wednesdays, the odd Saturday morning. The €70 days are Fridays and Sundays, when weekenders and the huge Moroccan diaspora in Catalonia all want the same seats.
What the cheap days cost you
Honesty section. A Tuesday €17 fare has real costs that don't show up in the fare: you might burn an extra day of annual leave to make the dates work, and Ryanair's hand luggage and seat games can add €20–40 if you let them. The fare is also, obviously, one-way — but on this route that's a feature, not a catch, because the cheap days outbound and the cheap days back rarely line up, and pairing two one-ways is exactly how you win. I've written up why round-trip thinking fails here if you want the long version.
Rabat is the arbitrage, Marrakesh is the benchmark
Part of why Rabat is so cheap is that everyone searches Marrakesh. Barcelona to Marrakesh is the famous route, so it carries the tourist demand and the tourist prices. Rabat gets the quiet fares — and it's a genuinely underrated entry point: the capital, on the coast, with a direct train line that puts you in Casablanca in under an hour and Fes in three. If your Morocco plan involves more than one city anyway, flying into Rabat and out of somewhere else is frequently the cheapest shape the trip can take. Morocco has a lot more airports than people think, and the gaps between them are where the deals live.
How to actually catch the €17 days
Don't check one date and conclude the route is expensive. Sweep the month: a flexible-date search on Flight Combinator shows the whole calendar for Barcelona–Rabat at once, and the cheap-day pattern jumps out immediately — it's not subtle, it's a €50 gap between adjacent squares. Then verify the specific day live, because cached calendar fares drift as buckets sell (more on that in how to read a price calendar).
The €17 flight is real. It's just perishable. The people who get it are not luckier than you; they searched by month instead of by date.