TheAirline.Models.Airports.Airport.GetTerminalPrice C# (CSharp) Method

        public long GetTerminalPrice()
        {
            long price = 500000 + 15000*((int) Profile.Size + 1);
            return Convert.ToInt64(GeneralHelpers.GetInflationPrice(price));
        }

        public static void CheckForExtendGates(Airport airport)
        {
            const int minYearsBetweenExpansions = 5;

            if (airport.Terminals.GetOrdereredGates() == 0
                && GameObject.GetInstance().GameTime.AddYears(-minYearsBetweenExpansions) > airport.LastExpansionDate)
            {
                Terminal minTerminal = airport.Terminals.AirportTerminals.OrderBy(t => t.Gates.NumberOfGates).First();

                bool newTerminal = minTerminal.Gates.NumberOfGates > 50;
                //extend existing
                if (!newTerminal)
                {
                    int numberOfGates = Math.Max(5, minTerminal.Gates.NumberOfGates);
                    int daysToBuild = numberOfGates*10 + (newTerminal ? 60 : 0);

                    long price = numberOfGates*airport.GetTerminalGatePrice()
                                 + (newTerminal ? airport.GetTerminalPrice() : 0);
                    price = price/3*4;

                    if (airport.Income > price)
                    {
                        for (int i = 0; i < numberOfGates; i++)
                        {
                            var gate = new Gate(GameObject.GetInstance().GameTime.AddDays(daysToBuild)) {Airline = minTerminal.Airline};

                            minTerminal.Gates.AddGate(gate);
                        }

                        airport.Income -= price;
                        airport.LastExpansionDate = GameObject.GetInstance().GameTime;
                    }
                }
                    //build new terminal
                else
                {
                    int numberOfGates = airport.Terminals.GetTerminals()[0].Gates.NumberOfDeliveredGates;

                    int daysToBuild = numberOfGates*10 + (newTerminal ? 60 : 0);

                    long price = numberOfGates*airport.GetTerminalGatePrice()
                                 + (newTerminal ? airport.GetTerminalPrice() : 0);
                    price = price/3*4;

                    if (airport.Income > price)
                    {
                        var terminal = new Terminal(
                            airport,
                            null,
                            "Terminal",
                            numberOfGates,
                            GameObject.GetInstance().GameTime.AddDays(daysToBuild),
                            Terminal.TerminalType.Passenger);

                        airport.AddTerminal(terminal);
                        airport.Income -= price;
                        airport.LastExpansionDate = GameObject.GetInstance().GameTime;
                    }
                }
            }
        }