StringBuilder Consume less memory than List<> in Generic

When I play around stringbuilder and list<> in generic I got small doubt in my mind. Which is takes less memory whether stringbuilder or list<>. However list<> is type safe even I eager to know which is takes less memory. Then i find out that stringbuilder takes less memory compare with list<> in generic.

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace ConsoleApplication1

{

    class Program

    {

        static void Main(string[] args)

        {

            long byte1 = GC.GetTotalMemory(true);

            List<string> lst = new List<string>();

            long byte2 = GC.GetTotalMemory(true);

            Console.Write("List Initialize :");

            Console.WriteLine(byte2 - byte1);

            for (int i = 0; i < 100000; i++)

            {

                string value = i.ToString();

                lst.Add(value);

            }

            long byte3 = GC.GetTotalMemory(true);

            Console.Write("List size :");

            Console.WriteLine(byte3 - byte2);

            StringBuilder sb = new StringBuilder();

            long byte4 = GC.GetTotalMemory(true);

            Console.Write("StringBuilder Initialize :");

            Console.WriteLine(byte4 - byte3);

            for (int i = 0; i < 100000; i++)

            {

                string value = i.ToString();

                sb.Append(value);

            }

            long byte5 = GC.GetTotalMemory(true);

            Console.Write("StringBuilder size :");

            Console.WriteLine(byte5 - byte4);            

            Console.Read();

        }

    }

}

please correct me if i did any mistakes.