Is it possible for to generate a value in a database base on the combobox item selected?

this is the whole code. from the moment the user pick the list of products in the cbproductdescription, i want to have a corresponding value or price that should already generated from the chosen product. is the code below possible for that kind of output? :))
try
{
SqlCeConnection connection = new SqlCeConnection("DATASOURCE=Database1.sdf");
connection.Open();
SqlCeCommand command = connection.CreateCommand();
command.CommandText = "INSERT INTO NewInventory(Product Description,Stock,Month,Model Number,Price,Total Cost) VALUES (@Product,@Stock,@Month,@Model,@Price,@Total)";
command.Parameters.AddWithValue("@Product", cbProductDescription.SelectedItem.ToString());
command.Parameters.AddWithValue("@Stock", txtQuantityInventory.Text);
command.Parameters.AddWithValue("@Month", cbMonth.SelectedItem.ToString());
command.Parameters.AddWithValue("@Model", txtModelNumber.Text);
if (cbProductDescription.SelectedItem.ToString() == "Prepaid - 300")
{
command.Parameters.AddWithValue("@Price", 7);
}
command.Parameters.AddWithValue("@Total", 0);
command.Prepare();
command.ExecuteNonQuery();
connection.Close();