new to arrays

Question

I am learning arrays and have a program that needs some help.  What I am trying to do is enter the miles of a trip then get a ticket price.  For example 0-99 miles would be $25, 100-299...$40,...300-499,...$55 farther than 500 miles is $70.  Here is what I have any pointers would be appericated.  I know I need to account for all the miles 0-500 Thanks

using System;
public class Miles

{
    public static string GetMiles()
    {
        string Miles;
        Console.WriteLine("Enter miles ");
        Miles = Console.ReadLine();
        return Miles;
    }
    public static void Main()
    {
        string Miles;
        Miles = GetMiles();
        int[] distanceMiles = {0, 100, 300, 500};
        double[] price = {25.00, 40.00, 55.00, 70.00};
        double customerMiles;
        int sub = 4;
        while(sub >= 0 && Convert.ToInt32(Miles) < distanceMiles[sub])--sub;
        customerMiles = price[sub];
    }
}