I had been doing everything on my own for the past 10 years, and felt I needed to expand into a physical location to get support staff and grow my business.

If you can find houses with weed growing through the walls like I buy, there is more opportunity cuz most people get scared off ;)

I'm in the Norwood area (with 3 commuter rail stops on the Franklin T Line) and $5-6 might buy you a smaller/older multi with 2-3 units.I would highly recommend you explore the Franklin area (Also on the Franklin T Line) as property prices are lower, there is a bustling down town, there is a growing college and there are is a large office park.

Those students will have to find outside housing now, so I've been looking into that area because I see its growing.

If you are looking to be a full time agent, your first year is typically slow, but then grows exponentially from there as you build your network and get your systems going.  

The time came (growing family) and we just closed on a new personal residence and paid for it using 80% LTV. 

Judging by my best case scenario I will have around 29 units about 6% to my goal, but the knowledge and connections will hopefully help this grow exponentially to help me reach this goal by age 35. 

A very popular price point would be 100K to150K ARV on an SFR...

Best option:  (I know it’s not single family, but it’s a super fast way to grow your equity AND passive income) buy a multi family (2,3, or 4 plex) as an owner occupant, live in it for the obligatory year, then buy another, until you just have to have your own house.  

There's a popular thread right now stating that the OP went from zero to fifteen properties in a year.