I am trying to have the cart subtotal display in the header of the master page. To do this, I created a token that returns the subtotal. Below is the code I used, but I want to make sure it's the most efficient way to do this.

Code:
private static string CartSubtotal(Customer ThisCustomer)
        {
            ShoppingCart cart = new ShoppingCart(ThisCustomer.SkinID, ThisCustomer, 0, 0, false);
            return Localization.CurrencyStringForDisplayWithoutExchangeRate(cart.SubTotal(true,false,true,true));
        }