The two numbers that matter: cap rate & cash-on-cash
Cap rate = NOI ÷ price — how hard the asset works unlevered. 5–8% is typical. Cash-on-cash = annual cash flow ÷ cash you actually wired — what leverage does to YOUR money. 8–12% CoC makes a deal interesting; negative means you are paying monthly to own it.
Estimates exclude appreciation, tax benefits and major capex reserves. Run real underwriting before buying.