Trade commisions

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp17
{
    class Program
    {
        static void Main(string[] args)
        {
            string town = Console.ReadLine().ToLower();

            double sales = double.Parse(Console.ReadLine());
            double comission = -1;

            if (town == "sofia")
            {
                if (0 <= sales && sales <= 500)
                {
                    comission = 0.05;
                    Console.WriteLine("{0:F2}", sales * comission);
                }

                else if (500 < sales && sales <= 1000)
                {
                    comission = 0.07;
                    Console.WriteLine("{0:F2}", sales * comission);
                }
                else if (1000 < sales && sales <= 10000)
                {
                    comission = 0.08;
                    Console.WriteLine("{0:F2}", sales * comission);
                }
                else if (sales > 10000)
                {
                    comission = 0.12;
                    Console.WriteLine("{0:F2}", sales * comission);
                }
                else Console.WriteLine("error");
            }
            else if (town == "varna")
            {
                if (0 <= sales && sales <= 500)
                {
                    comission = 0.045;
                    Console.WriteLine("{0:F2}", sales * comission);
                }
                else if (500 < sales && sales <= 1000)
                {
                    comission = 0.075;
                    Console.WriteLine("{0:F2}", sales * comission);
                }
                else if (1000 < sales && sales <= 10000)
                {
                    comission = 0.10;
                    Console.WriteLine("{0:F2}", sales * comission);
                }
                else if (sales > 10000)
                {
                    comission = 0.13;
                    Console.WriteLine("{0:F2}", sales * comission);
                }
                else Console.WriteLine("error");
            }
            else if (town == "plovdiv")
            {
                if (0 <= sales && sales <= 500)
                {
                    comission = 0.055;
                    Console.WriteLine("{0:F2}", sales * comission);
                }
                else if (500 < sales && sales <= 1000)
                {
                    comission = 0.08;
                    Console.WriteLine("{0:F2}", sales * comission);
                }
                else if (1000 < sales && sales <= 10000)
                {
                    comission = 0.12;
                    Console.WriteLine("{0:F2}", sales * comission);
                }
                else if (sales > 10000)
                {
                    comission = 0.145;
                    Console.WriteLine("{0:F2}", sales * comission);
                }
                else Console.WriteLine("error");
            }
            else Console.WriteLine("error");
        }
    }
}