There were also some gouges in the tile from a bed frame with metal feet. 2 hours with a power buffer and a total cost less than $200, and the entire floor looks like new again.

But to the north, west and south, there has (almost) always been a stock of housing that was more affordable than in Boston.But then all of that housing stock kept rising in price, and earning power didn't keep up. 

My goal is to be a full time RE investor and get financial freedom and good education for my 3 kids thru RE. 

Could be more difficult to cash flow as an investment property once you move out (if not renting out by the room)More affected by a vacancy (if not rented out by the room)More labor intensive if you rent out by the room.Not able to apply rental to increase buying powerMFR ProsPrivacy/separation from your tenantsStill have the ability to rent out rooms in your unit for extra incomeLess affected by vacanciesAbility to apply rental income to your income thus allowing you to increase your purchasing powerAbility to scale fasterMFR ConsMore expensiveCan be difficult to live rent free in high cost of living marketsCan be more difficult to sell (but not always and/or if priced correctly)Lending rules change when purchasing multiple units

Just based on what you wrote, it seems like you are looking for a way to get financial freedom without doing too much to get it.

Whats more, you'll note in national news that the freedom to wholesale properties on the whole is a hot target for the National Association of Realtors and many a duped home-seller. 

it is the most powerful way to get started. 

Owning real estate is one of the most powerful ways to build wealth, and with owner finance and subject to agreements, it doesn't have to be a difficult or complicated process.

The autonomy of controlling your time is so powerful.

For owner-occupied homes yes DTI will lower your purchase power-and I have a loan program where in case you have a good amount of assets then DTI will not matter.