Try networking locally with HML's who know the market. 

Depends on the market!

The rental market has slowed in recent months but expected in winter.

Also, we're not getting anywhere near market rent for the home since its only half the home being rented, however we do feel that we're getting what similar efficiencies are getting in the neighborhood.   

Pittsburgh has to be one of the best markets for house hacking so we are definitely blessed.

There's a reason that people try to buy properties off-market and that is because you can find sellers who care more about terms than maximizing returns.So start with a conversation: you already presumably have some rapport since it's your landlord and you've spoken before.

Warn them in the marketing (example: "This is an old house and noise travels between units.

You could put most of your funds in the stock market and access them when needed for a HML.

My first duplex was a turnkey, off market property.

A bit about me: I'm committed to learning the ins and outs of the market, and I'm not afraid to roll up my sleeves and work hard.