You need to know What Exactly this $20k bill is for, then work backward from there.

Mind you, they're already so deep in the train project that it's hard to see how they could go backwards on that one.

And folks from the mid west would say 3 to 4k  and some would say 5k with most folks thinking these days 10k is enough.. and then just as you say work the math backwards at 300 a month which is pretty tough to make if your max leverage and you have your answer of how many houses you have to own and manage.

I arrived at $450K based on working backwards to what loan amount at 80% LTV could be supported based on the rents and DSCR of 1.25.

I finished the book within two days and immediately realized my idea of wealth building was completely backwards.

This is backwards, since women tend to be physically smaller and thus more vulnerable to attack, and are the overwhelming target of sexual assault. 

I would start backwards from your purchase price and financing to narrow it down, go with a landlord friendly state and try to leverage anyone you know (family member out of state, friend doing BRRRRs out of state, etc) - that should narrow done your market quite a bit.

It sounds backwards I know, but welcome to NYC where real estate politics apparently matter more lol. 

They should be bending over backwards to make sure they represent your best interests and get you the best deal.

Taking 'effective' action is what you need to do next, find out what your goal really is and work backwards in discovering what you need to do to achieve it.