Two major benefits. 1. Tax claimable: cost that occurs during business set up, is called Business Development Expenses, is tax claimable. Costs that occurs after business already registered, is called operational cost, is not tax claimable. These costs will occur at any way, since these are mandatory filing, therefore, it's wise to include in package.
2. The default process is, these filing to be done together with corporation; hence, it's cheaper in package. To do this services later; there are manual forms and process; hence, costs more money and takes longer processing time.