error with Get and set

Question

I am trying to  figure out how Get and set works, and i am getting a error and i dont really understand why.

 

constructor with get and set 

class Accounts
{
    public string Nameinfo;
    public int Ageinfo;
    public Accounts(string aName, int aAge, string aprice)
    {

        Nameinfo = aName;
        Ageinfo = aAge;
        Price = aprice;
    }
    public string Price
    {
        get { return Price; }

        set {
            if (value == "1" || value == "2" )
            {
                Price = value;
                MessageBox.Show("good");
            }
            else
            {
                value = "0";
                MessageBox.Show("not valid");
            }
        }
    }
}

Button to activate the constructor

private void test_Click(object sender, RoutedEventArgs e)
{
    Accounts accountss = new Accounts("jack", 2, "1");
    MessageBox.Show(accountss.Nameinfo);

    accountss.Price = textbox.Text.ToString();
}