If you are getting a good deal on a place and it is just a regular-style house, I would run numbers compared to AirDNA and Mashvisor's estimated revenue.

As we evaluate deals, we're wondering if we're being too conservative with our estimates.

In my estimation it takes 2-5 years before a rental is broken in and feels like a good investment. 

Quote from @Aaron Wolman: I would call the companies (gas/water/electric) to get estimates, or an estimator out there.

By the way, when I reference "Boston" I also include surrounding towns like Everett, Malden, Somerville, Medford, Cambridge, Watertown, etc. 

bottom line - you can't use a square foot estimate... you need a bottoms up estimate as @Samuel Eddinger alluded to.  

On the surface, the deal seems appealing, but there's a catch: the asking price is $475,000, which is about 18% over the market value (based on comps and DealCheck estimates around $402,000).Details of the DealProperty: Duplex, 2,400 sq. ft., Purchase Price: $475,000 ($197.9/sq. ft.).Estimated Market Value: $402,000 ($168/sq. ft.).Financing Terms: 2% interest rate, with a 9-year balloon.Unit B Income: $2,049/month (Section 8 tenant through November 2025).Unit A Income Potential: Similar rent or higher; Section 8 cap for the area is $3,234/month.Monthly Loan Payment (P+I): $1,386.Cash Flow Breakdown (if both units are rented at $2,049/month):Gross Rent: $4,098/month.Vacancy (10%): $410/month.Operating Expenses (37.3%): $1,376/month.Net Cash Flow: $943/month.Key QuestionsWould you be comfortable paying an 18% premium for financing at 2%, especially in a market where current mortgage rates are closer to 7%?

Rehab estimated at $35K3 unit propertyWill need some financing What made you interested in investing in this type of deal?

Wanting to know who we can reach out to for management, estimates on potential income/expenses. 

They care about what they estimate it would cost to rebuild the home.All else being equal, yes, older homes are more expensive to insure than newer homes for a variety of reasons.