If your goal is to have 1 or 2 rentals as supplemental income as you age, then I agree paying off all debt sounds great. 

This is better than I expect the mutual funds in my 401k portfolio to perform(10-12%) Plus I would like to eventually use some of the cash flow to supplement my income before retirement age. 

Why is that I can buy a SFH at 640k no problem, but I cant buy a triplex even though I have been approved to make the mortgage payment without even considering the supplemental rent if I had to? 

Are you looking to bring in cash flow to supplement/replace income?

We would have to supplement the rent for a few years, but these properties are million dollar homes with great value.

Then, rinse and repeat.When designed and implemented properly, you should be able to purchase multiple properties over the years, and still have a way to supplement your retirement in the end with the cash value.Feel free to reach out with any follow up questions.

Use the money you will be making within the oil field and put it towards building a real estate portfolio with sold cash flow that you can use as supplemental income once the oil field turns and money is harder to come by again.

If cash flow would go negative following a refinance then it will be up to you to decide whether or not you want to keep the property and accept a negative cash that you will need to supplement in the short term because your goal is long term appreciation in the area or whether you would rather regain your capital and take the immediate profits in order to put into another property.

We still do mailers to supplement our campaigns but might stop soon. 

The idea is to live in an up-and-coming market for a few years while I work (energy engineering/flight instructor) and use my investment to supplement my entry-level income and accelerate my financial goals.