I have thought for a long time that there are basically two cities - river ones (like Glasgow) and coastal ones (like Edinburgh). But Edinburgh's too deep in my bones for the river model to work as generic for me.

On the subject of the Sheffield to Stansted via Berlin routing:

A Boeing 737-800 (10 year old short-haul airliner) burns 600 US gallons of fuel per hour (call it 2700 litres), and carries 180 passengers max. It flies at 500 knots (call it 850 km/h). I make that 153,000 passenger-km/27600 litres = 56.7 km/litre/seat.

Let's round it down to 50 km/l/s, to take into account extra take-off/landing cycles on short-haul (it can actually fly for about 6 hours on a full fuel load but the UK-Berlin flights are less than 2 hours).

Civil aviation costs break down as typically 33% airframe depreciation, 33% maintenance and crew costs (they're labour intensive) and 33% fuel. So a good rule of thumb is to calculate the fuel burn per passenger on a route and multiply by 3 for the actual price.

Stansted to Berlin (similar to Berlin to Sheffield) is 1130km. Call it 2300km for the round trip. That gives us 42 litres of fuel burned. Fuel is currently on the order of £1/litre at the pump in the UK -- with tax, which doesn't apply to aviation fuel.

So our traveller paid a bit more than the price of fuel for his trip, but although the airline probably made a loss on the ticket by not covering their airframe/payroll costs, they made much less of a loss than if they'd flown with the seat empty (which is why budget airlines almost always fly with every seat full, even if they have to sell the last ticket for £1 -- flying a jet on a given segment is a fixed cost, and once they've covered it every £1 extra is £1 in profit -- or £1 less in loss).

Break-even for that route is probably closer to £90, but I can see how the £42 fare happened.

Being as both me and several of my friends are under-car-ed and under-monied, we know of the insidiousness of rail fare rises. There are a few work-arounds that the article completely misses, like early booking (which often includes accepting your fate and travelling at either crack of dawn or crack of midnight) or checking several station combinations to get the cheapest.

I say this mostly because I've organised Leeds to Stanstead for a lot less than that.