Agreeing with everyone above, I will add that yes some products do not follow the traditional path. Some products may not cost you a lot during any of the phases and end up giving you the most increase in sales and profit at the end. While some products may be very expensive during the research and development phase and you think everything is in place but they end up never making it to the market during to a issue with the product. This is where I believe a project manager emphasizes on the initial phase and making sure everything is in place and resolve any potential problems that may arise in the later phases. So its not always about the expense in the phase, its about making sure each phase is accurately completed.