It's an estimated cash on cash return given current rental rates subtract expenses assuming 7% interest rate, 10% management fee, 5% repairs, 5% capex and other expenses like mortgage, insurance, tax. it's a estimate to tell you what properties to analyze vs ignoreyou can see the are pockets of negative returns as well as pockets of positive return. this is to supplement the data @Devin Conley provided

What if the smell was coming from a broken sewer line that was back-gassing into the unit, as well as leaking all around the foundation and rotting wood beams.

That's actually one of my pieces of advice for you... learn how to do your own book keeping so you know your P&L in real time at all times. 8) Hard to say without knowing the value of the place, CC&Rs, as well as any HOA fees/dues. 

I do know Walter and have known him for more than 25 years, he is upstanding and he is smarter than the average bear, he's in the deal to help people and I have learned an immense amount from him I am now 67 years old and I bought my very first home by having my parents cosign!

p.s. thank you @ScottTrench for your guidance as well!

With future income you pay off that loan as well.

Or, you'll get so well known that other investors will want to fund your deals.Below is a piece we wrote about how to build your network and search for deals.

If you discovered the issue before paying for the appraisal that could hopefully save some costs (in case the appraiser is with the wrong AMC).Pre-vetting with the lender on rental history/AIRbnb/1007 as well as seasoning could help. 

When I see ones much more than that like yours in the $700s to well over $1000, run.

I think you should be paying about 10.5%-12% on average right now, 1-2 points as well, and some lenders will not even need an appraisal.