@Paul Bogard going to assume you are buying this proeprty to live in while you "house hack".First, you should understand +95% of real estate agents ONLY know how to sell owner-occupied properties and are almost useless for investors:(Find an agent that has rental properties themself or can PROVE they've got successful repeat investor clients.Secondly, you can greatly improve your cashflow by renting out your other bedrooms.

Not sure what Orlando is without looking, but Atlanta market is between 80-90% occupied.

You can get far bette financing for own occupied properties.  

There is no differential factor number, however, it will change if you are buying tenant occupied, if they are are going to be vacant at closing, if they are going to stay the full lease or you have to pay cash for keys.

Now assume each unit is occupied by 1 person.

Finance your first duplex or triplex through FHA Loan, Conventional Loan, Owner-Occupied Financing, and Portland-specific programs.

She has a duplex, one unit was owner occupied until her stroke; other had been rented until the same timeframe.

Since the houses are occupied and the first is reaching its contract limit of a year, its time to renew, increase the rent and I don't even know how to.

The best part is you can do it with very little money down using owner occupied loans. 

Many houses and duplexes that have been fully redone as well as some that are still owner occupied that will get redone when purchased.