I assume the plumber covered his butt to make sure he'll get paid and won't fix this without seeing payment.

I know when my G shepard bit a lady on the butt who walked into our house without permission and she filed a claim the insurance company would no longer insure the dog.. of course we owner occ so we kept Tessa loved that dog... was not the end of the world.  

Hope this doesn't sound like some pie in the sky artsy fartsy eternal optimist response (because it kind of does in my head, and I don't mean it to), but maybe just a plug for a good starting point to get you facing in the right direction.

You need to look at the listings, ask about rent rates for that specific property in that specific neighborhood (don't simply rely on Rentometer or BP's rent estimator), and plug them into your BP Calculator/spreadsheet/etc.

Problem: tenant can not was our dry clothes, fuse keeps blowing.Technicians notes: you had 3 issues. 1) panel buss shorted. 2) dryer plug bad. 3) Dryer receptacle shorted.

Streamline your analysis system - put together an initial spreadsheet that lets you quickly plug and play, I've furthered the speed of this by adding in some lightweight VBA, a "clear" button, that lets you plug and play to run analysis fast - finding your ways to speed up your own internal process is important. 3.

People like it way more than I do, and I created it :) Thanks for the plug!!

In short, get plugged in.

SO, regardless what you do, I would get plugged in with some guys who are more experienced than you and are doing what you want to do. 

An investor comes in, looks at the prices, crunches some numbers, plugs in the $30K rental history and declares lack of cash flow :-).