Cap Rate & Discounted Cash Flow Analysis for a real estate property I may be selling

I may sell a large property with 3 units and 13 bedrooms that is currently in very bad shape. I have been in the real estate business for a long time, but I have generally dealt with smaller properties... (Budget: $74 - $75 USD, Jobs: Economics, Investment Management, Market Analysis, Property Management, Real Estate, Valuation & Appraisal)