The return you should expect is dependent on lots of factors, but it can be double digit.  

If deceased, there are a number of factors that must be established.

@Matt Huber I think some of what you're seeing has to do with some different factors.  

However, $300 is nothing and it would take me forever to save up for a 4th property, let alone convince the bank to give me yet another mortgage.That's why I feel stuck when I try to envision my future and draft out a plan.

You would need to factor in repairs and CapEx though. 

Depending on a couple factors, you can certainly get better terms than 14/4.  

Deciding factor will likely be cash flow. 

Will or no will, high value or low value, multiple heirs or a single child, mortgages or no debts, all these things will be factors in determining the complexity of the case.Since you'll need to know the next of kin (either directly or obtained from death certificate) you'll also need to think through what you'd say to someone who just lost a close relative. 

I agree with David that wholesaling is a full-time job... but, it's not meant to be that way forever.

I've been doing taxes for ever, and thought that if you paid off your rental mortgage your taxes would be increased due to all of the rental income being profit (except for the operating expenses).