Once in a while you get an older person who has become dependent on it as a source of retirement income (hint hint btw: selling point of seller financing - a vehicle for retirement income).

I know this will be hard to give a precise answer on, I'm just looking for rough estimates based on your experience.So by the end of the year I will have 12 rentals, single family homes, located on two properties, one in Maryland, one in Virginia, each about 45 minutes from my home.

For instance, funding A with your reserve checking account and funding B using your business line of credit.Essentially, I am getting that a good rule of thumb is the one should generally not work on more than a deal at the same time, regardless what the aggressiveness and risk profile the investor has, precisely because the underwriter can pull the rug unexpectedly at the last minute, and we don't want that.In my example, A has to close first before resuming talks with B (assuming the market hasn't taken over B yet).

But these are two totally completely different vehicles, which prompts me to say, maybe your experience as an agent will be different than the other 80-90%?

In your opinion please help me understand the benefits of each vehicle to defer taxes.  

Also I'm not sure what the "opportunity value" represents... investment vehicles with 10% ROI aren't just falling from the sky in my neck of the woods.

The way I looked at it (at the time) was that $4,500 invested in the stock market or any other investment vehicle would never earn me a $6,600 annual return.So, basically for $4,500 out of pocket, I purchased a 3/2 rental property in a good neighborhood, got a low-interest 30 year mortgage that the tenants are paying off, created $23,000 in equity, and net $6,600 (before taxes) per year.

Lots of other vehicles that create your financial picture that can help grow your net worth along with RE.I hope my response helps.

I'll tell you that the property is located in a small border town called Eagle Pass, Texas with no more than 35 thousand people. [434 Ryan Street, Eagle Pass Texas] Its location (in my opinion) is in an excellent spot known for weekend flea market activity and sits right across from a well-known local park; however, weekday vehicle and foot traffic is essentially non-existent.As far as the flea market goes she's been running into huge problems with vendors remaining loyal to their current flea market. 

I like to be precise as possible when dealing with this type of information because it could make or break a potential deal.