using System;

using System.Diagnostics;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        Stopwatch s = new Stopwatch();

        s.Start();

        //Current method

        var original = Enumerable.Range(0, 1000);

        var listWithADifficultSelect = original.Select(aMethod);

        var onlyOneItem = listWithADifficultSelect.ElementAt(898);

        Console.WriteLine(s.ElapsedTicks);

        s.Reset();

        s.Start();

        //Current method

        var original2 = Enumerable.Range(0, 1000);

        var onlyOneItem2 = original.Skip(898 - 1).Select(aMethod);

        Console.WriteLine(s.ElapsedTicks);

        s.Reset();

​

    }

​

    public static object aMethod(int number)

    {

        // Gets the item from some kind of database, difficult operation

        // Takes at least a few milliseconds

        return number;

    }

}