I'm really curious as to what the average ball park cash flow per month would be for a small duplex that is fully paid off?

It sounds like you're into a portfolio lender situation, which I agree would definitely change the ball game.  

WIth subject to, you hope the lender never finds out and the seller remains responsible.The risk is that the lender does find out and exercises their right to call the loan.  

But that is unlikely to happen anytime this decade.But, ultimately, while both of us like to believe we have a crystal ball and can see the future, we are both simply guessing.

However as a listing ages and especially if there have been no offers (you won't know this) they may accept a low ball offer or countered at a very good price. 

You may be looking at only the value of an option as a financial derivative and not the value of exercising the option, the full value is not included.4.

Looking for some good mentors and guidance to get the ball rolling.

Good photos, online video tours, and social media advertising are where so many drop the ball. 

You would still have to put time and money into maintenance, TIs and lease ups but at least you're compensated by not tying up a downpayment and getting an instant equity boost when you exercise the option.

I researched what i could, seems like IRS stand in line chronologically only having right of redemption. but if they don't exercise it,the lien follows the property ?