I currently have a mortgage free duplex in Lowell, MA in what I would describe as a B-/C neighborhood. 

20-100 unit value add deals in A/B/C areas.

My friends were paying $900 for a room in a B- class apartment a mile from campus.

Hey Folks, Recently bought my first multi in New Haven, CT, I'd say it's a B class property in a rougher C class neighborhood.

Long story short I was able to access the money through a B lender and made a very high ROI on my next deal.

You got  a B not an A on that unit on some occasions. 

The area is currently turning from a B area into an A area.

The home is in a b+ neighborhood that's surrounded by A homes. 

You could find a single family home in a B class neighborhood for $94k or possibly an A class but the home will need work, but it won't generate $500/mo in cash flow.

The SB and AB's that were passed for ADU's were much more effective in creating additional housing, but still just a drop in the bucket for what is needed and the costs to build the ADU's are skyrocketing each month due to labor and materials costs, not to mention material shortages due to supply chain issues which are getting worse, not better (that's across the board for all states, not just CA, but more heavily felt here as Long beach is a HUGE port not currently even close to full operations.)