how to let me get the Total Price from the bus ticket?

protected void btnBookSeat_Click(object sender, EventArgs e)
    {

        if (Session["basket"] != null)
        {
            Basket_DataTable = (DataTable)Session["basket"];
            Basket_DataTable.Rows.Add(new object[] { ddlFromCity.Text, lblPrice.Text, txtJdate.Text, cblTime.Text, ddlSeat.Text });

            Session["basket"] = Basket_DataTable;
            GridView1.DataSource = Basket_DataTable;

            GridView1.DataBind();

        }
        else
        {
            //create an empty DataTable and Add some columns to it
            Basket_DataTable = new DataTable();
            Basket_DataTable.Columns.Add("BusRouteID", typeof(string));
            Basket_DataTable.Columns.Add("Price", typeof(double));
            Basket_DataTable.Columns.Add("Date", typeof(string));
            Basket_DataTable.Columns.Add("Time", typeof(string));
            Basket_DataTable.Columns.Add("SeatNo", typeof(string));
            Basket_DataTable.Columns.Add("Total", typeof(string));
            Basket_DataTable.Rows.Add(new object[] { ddlFromCity.Text, lblPrice.Text, txtJdate.Text, cblTime.Text, ddlSeat.Text, });

            Session["basket"] = Basket_DataTable;

            GridView1.DataSource = Basket_DataTable;
            GridView1.DataBind();

                    }
    }