Losing TextBoxFor value when using String.Format()

When using the following code MyValue is lost when the view model is sent to the controller.

@Html.TextBoxFor(x => Model.MyValue, new { @Value = String.Format("{0:N0}", Model.MyValue) })

When I remove the String.Format() portion the value is passed correctly. Fyi, MyValue is a double.

How can I pass MyValue while retaining the formatting?

I've tried using a separate HiddenFor but this did not work. Also, I suspect if MyValue where a string instead of a double, the value would be passed. However, for now I'd rather keep it a double unless there is no easier way.

Edit

Unfortunately I'm still having the same problem. Here are some more details of the situation.

The following code works fine when I enter a number (e.g., 123456) without commas: The number is sent to the Save action of the controller and 123,456 is displayed in the Text Box. However, when when I click Save again, and try to enter the number 123,456 with the comma, the Save action only receives a zero in the model parameter and a zero is displayed in the Text Box

What am I doing wrong?

Here is the Model:

public class FormatTextBoxFor
{
    public double MyDouble { get; set; }
}

Here is the Controller:

    public class FormatTextBoxForController : Controller
    {           
        public ActionResult Index()
        {
            FormatTextBoxFor model = new FormatTextBoxFor();
            return View(model);   
        }

        [HttpPost]
        public ActionResult Save(FormatTextBoxFor model)
        {
            return View("Index", model);
        }
    }    

And the View:

@using (Html.BeginForm("Save", "FormatTextBoxFor", FormMethod.Post))
{
    <p>@Html.TextBoxFor(x => x.MyDouble,  string.Format("{0:n0}", Model.MyDouble) )</p>

    <input type="submit" name="submit" value="Save" id="submit" />
}