Any time you can get into a project with no cash investment and positive cash flow, it's still infinite cash on cash returns.

Do you want the safe return or are you wanting to risk some of what you've earned so far to get more? 

They calculated their return at 13%.

My rental business is only a year old therefore it seems I can’t get a bank loan before I get two years of tax return. 

Also, if they leave the place without damages, clean, and ready to rent (quick turnover), then I would consider returning the security deposit.

Before I was planning on buying a house back home earlier in the year and renting it out but instead of dropping a large down payment I could put that money in a few notes for a much better return.

I make a higher return than on most my other properties.

I would like to grow a portfolio of properties over the next 5 years with cash on cash return as a focus, cash flow positive properties, and value add properties (fixer uppers). 

Should it not be on the monthly cash flow and look at the numbers for cash on cash return and cap rate?

I can give hard numbers upfront and what to expect on return.