We're exploring adding garden units, but it's less than likely due to the fact the city (Chicago) is notoriously difficult on these matters. 

That would give me a negative cash flow of $300 with a gardener and a pool guy.

Initially, I had thought of buying the property, fixing it and renting it, but now that I have actually spent time and driven around Miami Gardens, I’ve changed strategy to just flip it.

Rehab finished......Garden: Floor 2Coach House - Huge Master 

Try Spring Garden Capital in Philly

@Mike Dymski great points.I worked for a SF BAy AREA syndicator in the mid 80s  there model was garden apartments 10 to 30 units.. you can probably picture those .. they had about 300 properties.. from San Jose to Sacramento...

I'm partial to the South end- Murrells Inlet, Garden City and Surfside but work up and down the coast.  

Mgmt: $235 (10%)Prop tax: $262.50 (Rochester NY has 3% prop tax)Repairs: $117.50 (5%)Water & Sewer: $120 (figured $30mo per unit)Insurance: $75P&I: $425.62 (30yr 4.5%)Misc: $60 ($120 month  for a gardening for 6 month season)Not including snow removal$2350 Rent-$1802.12 Expenses$547.88 Cashflow (with 20% down)Looking at the 50% rule you mention it would indicate that I should cash flow approximately $1175 if it was purchased in cash.

As a gardener-a-holic and former landscaper, grass is cheap. 

One day last year, when I had my gardener cleaning my yard, the neighbor came and talked to my friend about the tree root problem.