set quote product price manually and not using pricelist

Hi

I create a quote by code, and I add its product as follow, I want to enter product price manually and not using Price List , but I dont know how to save "Currency" value into "Price Per Unit" attribute. 

ntity quotedetail = new Entity("quotedetail");
                quotedetail["quoteid"] = quote;
                quotedetail["productid"] = new EntityReference("product", GetProductId(item.Product));
                quotedetail["quantity"] = Convert.ToDecimal(item.Quantity);
quotedetail["priceperunit"] = ??? 

                quotedetail["uomid"] = new EntityReference("uom", GetDefaultUnit()); 

                service.Create(quotedetail);

May I use type casting like (float)productprice ?