I checked the air ticket from Beijing to Dalian on March 25th for you. The lowest price is air ticket 270 yuan+engine oil fee 130 yuan, and the price is within 400 yuan. The lowest airfare from 26th to 28th is 200 yuan (the price can be found on the airline website).
The cost of infrastructure and fuel is 130 yuan or 190 yuan respectively, and the difference is based on the air mileage, that is, the distance between the two places. With 800 kilometers as the boundary, it is 190 yuan if it exceeds 800 kilometers, and 130 yuan if it is below 800 kilometers. Airport construction fees and fuel surcharges are relatively fixed, charged according to the fees stipulated by the state, and generally will not change.