Running out of gas is one of those things that happens to almost every driver eventually. Fuel delivery is the fix — a technician brings 2–5 gallons of gasoline or diesel in approved fuel containers and pours it into your tank.
Cost structure: the fuel itself is billed at local pump price plus the standard service rate. There's no inflated 'emergency fuel' markup. If gas costs $3.50/gallon, you pay $3.50/gallon for the fuel.
Once the gas is in, the engine usually cranks within 10–20 seconds. Some vehicles need a minute and a few crank attempts to clear vapor lock after running fully dry. Most fuel-injected cars start more quickly than carbureted older cars.
Running fully out of gas isn't great for your fuel pump. The pump is normally cooled by the surrounding fuel. When the tank goes dry, the pump runs hot for the last few minutes before the engine stalls.
Diesel-specific note: after running a diesel dry, the engine often needs the fuel system manually bled to remove air. Most modern diesels have an electric auxiliary pump for this. Older diesels need a hand pump and bleed screw.