Any stains on the walls, ceilings?

For example, I looked at 2 duplexes on the same street.

Both bathrooms have mold/mildew growing on the walls and ceilings.

You might even find a couple of duplexes as $80 might be enough for downpayment. 

What is the best way I should go about finding a duplex, triplex, or 4-plex?

Some work I would need done would be some tile replacement in a bathroom shower, a leaky sink faucet replaced, and kitchen fan replaced / fixed, and possibly (I am undecided here, depends on how much the previously-listed runs for cost) some framing done - My property was originally built as a single-family home and split into a duplex, but shutting off / sealing off a door, which is still a door.

@Jeremy M. this is plaster and I didn't check the walls at all, but I expect to find some there.

We've always purchased turn-key properties and are now thinking of buying a true fixer-upper at a lower cost and renovating (i.e. adding higher, architecturally interesting ceiling, ripping out walls, and designing a modern space, etc.). 

Needless to say, the walls didn’t come out flush.

Am in escrow on a duplex set to close in 2 weeks and went into contract on 2 SFR this afternoon.