Hello Lior, what a meticulous due diligent you've done, great job! However while data crunching is always good, also remember there is almost, always a lag between when the data was generated and the present existential reality on the ground. I do own a one apartment condo unit in North-Quincy, 644 sq feet, renting for $1550. Actually there were people willing to pay more. There is also a multi-family house close to me, the 2bedrooms in that house are going for $2050.
Timing and proximity to the Redline train, are the 2 biggest factors that determine the rent pricing. Mine was in the market for less than a day in last July, and I got multiple offer, more than I had expected. Will this trend continue? I have my doubts with the rate apartment building developers are pouring into Quincy, I fear the market might become over saturated in 2 to 5years time.
That said, I think I prefer multi-family over single unit, because of the higher rate of returns on investment.
I wish you the best with your venture!