public class PriceManager 

class MyPage : System.Web.UI.Page
{
    private Dynamicweb.eCommerce.Products.Product product;

    private void Page_Load(System.Object sender, System.EventArgs e)
    {
        product = (Dynamicweb.eCommerce.Products.Product)Session["Ecom.Backend.Product"];
    }

    private Dynamicweb.eCommerce.Prices.PriceInfo GetPrice(ProductItemCollection items)
    {
        Dynamicweb.eCommerce.Prices.PriceInfo priceInfo = new Dynamicweb.eCommerce.Prices.PriceInfo();

        if (product.Type == ProductType.Stock & product.PriceType == ProductPriceType.Calculated)
        {
            product.PriceType = ProductPriceType.FixedPrice;
        }

        if (product.Type == ProductType.Service & product.PriceType == ProductPriceType.Calculated)
        {
            product.PriceType = ProductPriceType.FixedPrice;
        }

        if (product.PriceType == ProductPriceType.Calculated | product.PriceType == ProductPriceType.CalculatedWithBase)
        {
            foreach (ProductItem Item in items)
            {
                object priceObj = Dynamicweb.eCommerce.Prices.PriceManager.FindPrice(Item.Products.getProductById(Item.DefaultProductID), Item.Quantity);

                if (priceObj != null)
                {
                    double quantity = 1.0;
                    if (Item.Quantity > 0)
                    {
                        quantity = Item.Quantity;
                    }

                    Dynamicweb.eCommerce.Prices.PriceInfo subPrice = null;

                    if ((priceObj) is Dynamicweb.eCommerce.Prices.PriceInfo)
                    {
                        subPrice = (Dynamicweb.eCommerce.Prices.PriceInfo)priceObj;
                    }
                    else if ((priceObj) is Dynamicweb.eCommerce.Prices.PriceRaw)
                    {
                        Dynamicweb.eCommerce.Prices.PriceRaw rawPrice = (Dynamicweb.eCommerce.Prices.PriceRaw)priceObj;
                        subPrice = new Dynamicweb.eCommerce.Prices.PriceCalculated(Item.Products.getProductById(Item.DefaultProductID), rawPrice);
                    }
                    subPrice = subPrice.Multiply(quantity);
                    priceInfo = priceInfo.Add(subPrice);
                }
            }

            if (product.PriceType == ProductPriceType.CalculatedWithBase)
            {
                priceInfo = priceInfo.Add(new Dynamicweb.eCommerce.Prices.PriceCalculated(product));
            }
        }
        else
        {
            priceInfo = new Dynamicweb.eCommerce.Prices.PriceCalculated(product);
        }

        return priceInfo;
    }
}