How do you go about checking if a property exists and has value? "HasValue(string)" seems to only check if the property exists at all?

@if(@product.Node.HasProperty("productSalePrice")){
                  <span class="price">Price: <span class="salePrice">@product.OriginalPrice.ToString("C")</span> @product.Node.GetProperty("productSalePrice")</span>
                       } else {
                      <span class="price">Price: @product.OriginalPrice.ToString("C")</span>
                }