In my experience, a successful BRRRR typically comes down to two main things: finding a good deal and managing an efficient renovation.

But let HIM earn it.

For example, if the typical rent per unit is $1,500 (3bd 2ba), my landlord at the time would have one unit with three rooms and four people within the unit (one person per room and one room with two people), each paying around $500.

The typical income from a free and clear rental would probably be $800-1500/month - and on a financed rental probably $300/month on a good day in today’s market.  

We typically pay somewhere in the range of $3500 for a new, basic furnance, including install, if there are no other modifications to the system required.  

That's a typical scenario and could cost you $10,000 - $15,000 so that would be a good starting point for your reserve.But there's more!

They don't typically throw parties there like they would at a fraternity house.

Never heard of a voucher tenant being responsible for maintenance and repairs, rental licensing fees, lead testing upkeep, cap ex, reserves, book keeping and tax prep......and even if you self manage, it takes up your time and should be treated as an expense because its taking away from your ability to earn income elsewhere. 

It's people who understand that it takes effort to become successful, typically from CA at this point, and have a way of showing those characteristics, do best.

Additionally, there typically are additional state protections (outside of the agreement) based on where the fund is located.