Pick a business and go interview owners of that business. If it is a school project they will probably be more than happy to share percentages and line items to help you build a realistic P L (profit and Loss statement).Also, go to the library. There are resource guides that give ranges of expense for certain business and industries.They will also tell you the types of advertising that works best for their business. Billboards are really expensive. They are totally out of the reach of small to medium size businesses.. If you go with a bakery you are likely looking for street fairs, open houses, catering for business meetings, word of moth and limited advertising as you will not have the capital resources to spend on advertising as it is low margin business.
these are all things you have to research yourself, i.e. the cost of renting commercial space in your area, the cost of an oven from sears, the cost of wages to employees, the cost of an ad in a newspaper, do some work yourself...
at least $10,000
