Well I don't know anything about tycoon, but I doubt that you'll find any sort of studies or formal guidelines for this sort of thing. If your lucky, perhaps you can get in touch with some project managers from existing game studios who could give you their opinion, but every game project is different, each with its own unique challenges. How long it will take and what it will cost depends more on how skilled, motivated, and organized your team is than it does on how many team members you have. The best estimate of how long something would take to create is going to come from the people you wish to hire to do the work. Hiring people with demonstrated experience costs more, but you can also see in advance what they can do, and can find out how long it took them to do it.