The answer to this really depends on what you're working to achieve in the 12 weeks.
If you're looking to lease a new studio space and hire a new teacher, you're going to be investing much more than if you're planning to organise your resources and sheet music and develop a long-term curriculum.
And it will be different again if you'd like to develop a new website and setup marketing automation as you'll have a variety of new hosting and software costs.
Your coach will be able to help you estimate your investment and provide recommendations for service providers and contacts. You may also be able to access discounts either through the Top Music Pro discount program or via your coach's own networks.