I found a legal non-conforming triplex listed as a duplex in East Millcreek, UT (SLC). I closed on it for about $370k when it appraised for $440k. I have also added some sweat equity in the form of refinished original hardwood floors and new paint throughout. I also updated the two attached 1 bed, 1 bath apartments. I'm using an Airbnb strategy in one and a standard 1 year lease in the other. I am living in the 4 bed, 3 bath unit with my wife and 3 kids. While I know my find is extremely rare, it's important to note that a little bit of research goes a long way. Also, look for properties that have been, "well loved," but not trashed as another way to negotiate costs at closing. Approach the properties with vision and you will find opportunities to cash flow. Especially if you decide to furnish the apartment(s) and airbnb/VRBO the properties. There is a ton of potential to earn a lot more income with this strategy.
@Mike Mack is right though, with this strategy there is more risk in that you could be carrying more of the mortgage throughout the year, but if you do it right, you will come out on top with a profitable investment.
PM me if you want any more info. House-hacking is a no brainer. It's worth the $30/Mo. for the Rental Property Calculator. I am a Realtor now, but I used this awesome tool when I wasn't and it made a huge difference in the time I spent on analyzing deals.
@Brandon
@Brandon Turner says we need to be analyzing about 100 deals a month if we expect to find the good ones. Best of Luck!