What are some of the costs related to the installation of three phase into an existing building not previously wired? This particular install would be for both 240 and 480v. Thank you

Check with your power company before you get to involved to see if it's available at your location and if they will allow you to have it. There's a lot of things that affect the price of a new service. What amperage do you need? How many circuits? How much cable/conduit wire will be needed? Will a transformer be needed for 120 volts? You will most likely need a qualified electrician to look at the project and give you a quotation.