It is currently a 4 unit, 2 units on each floor, and after my initial walk through of the property I noticed a HUGE unused attic that can convert into one if not two additional units. 

From what I can see this is not an option, the listing agent will reject this immediately.

However, your initial payment and security deposit may take some time before it hits your bank account.

Other than Mashvisor, are there any other tools that can automatically filter out any new MLS listing based on my criteria (e.g rent avg, cap rate, expense)?

Go to your Sewer Districts website for a list of qualified contracts accepted by your municipality.

For example there's a property that I know is in a GREAT area here in Buffalo, huge 2 unit house with potential for a 3rd unit listed at ~150k.

@Jen Mendez what a great initiative.

Michael, something I want to add to your spot-on comments; I see a lot of inexperienced STR buyers, buying a property to be a STR either on their own (FSBO or through the listing agent), or through a buyer agent that has little to no experience with STR's and who doesn't have a a great STR network, strategy, has no ability to analyze a property's STR potential, doesn't know how to assess and recommend remodel or what it will cost or how long it will take and what's required by city/county, etc.

Despite the initial setbacks, we got a remarkable cash-on-cash return of 37.5%, far surpassing industry standards: Cash-on-cash return (Hammond Townhouse) = $12,000/$32,000 = 0.375 = 37.5%.

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