P M,
You have following costs: property taxes, insurance fees, common electric, water, sewer, trash (don´t pay the heat for your tenants!!), lawn and ground keeping, possible advertising, accounting, permits, licenses, maintenance and the biggest problem vacant units or not paying tenants.
This is all expenses, on a two unit can these expenses be low and not 50% of the rental income, but the best is you plan with these.
My calculation with a 10% CAP is, when I pay the house in full (here $57,900) and leave the NOI income untouched in the bank account I paid the house after 10 years.
I don´t calculate with rates longer than 20 years and I will buy and hold forever. So your payment with 20 years would be $415 monthly (6% interest) and you have an cash-flow (income) of $812 yearly, at 30 years ($347 payment) you have an cash flow of $1,624. Thats unusual I know, but we work different in Germany. Longer payment years = higher interest to pay (for 20 years you pay $41,656 only on interest, with 30 years you pay $67,070 for the interest) huge sum eh ($26,000 more)?
Its clear a two unit can be have lower expenses than 50%, I think 40% is a good mark. The best is on your buisness plan you calculate with 50% and you become every year an nice bonus.
Reserves for a two unit should be $4-5k no more, if the house fully rented now and the leases longer than 6 month.
And Norm, I dont think you can the owner persuade to lower his sales price significant. In Jon´s case ($43,000) with 20% down payment such as $55,000. A minus of $15,000 and the seller says definite no. Okay a two unit is not the investment type to gain wealth, but you must calculate with a CAP on any investment.
-Uwe
P.S.: Sorry my english is not so good, but I hope you understand the explain from me.