Hey @Par Attaran, if you are going to possibly invest in San Antonio, I think you should take a flight over here and check out the different areas FIRST.

Any big ticket items like A/C units, roof, etc.

There has been a lot of residential flight from the area as a result. $1300/month seems absurdly high as this is a relatively low-income/working class area.

A flight and a Friday off work is a small price to pay for missing a bad down payment.

The general consensus is to improve the big ticket items (painting, flooring) once the units are vacant. 

Kyle,Your ambition is commendable--just make sure you give the proper time and attention to learning whatever your military trade is going to be; these are formative years for your military career and you don't want to neglect your training (I was in flight school at your age and there's no way I could have thought about real estate investing).That said, you need to decide your specific real estate ambitions and then chart out how you want to get there. 

Can you guys please review my math and let me know if there are any "blatantly wrong" assumptions or missing big-ticket line items?

This property is now renting at $750.00 and after expenses, including taxes and a portion for big ticket items, I walk away with $550.

Chuck, 100,000 is my flight training and 50,000 is my wife's marketing degree.

Other types of investment (in land in private developments, or in a house in a place like PlayaCar) where the ticket price on the house is upwards of $500,000, financing through a mortgage broker like Mexlend or several others wouldn't be a problem.