.- My Resources / Constraints: I'm in a by no means unique, but perhaps less common situation for those getting started; I'm a somewhat senior software engineer at a tech megacorp and should be able to save a couple of down payments per year for lower priced houses (100-200 in my area), or perhaps one medium priced house (300-500).

I will be graduating with a degree in Digital Marketing and have been applying to jobs for a while with not much luck.

That allows the payment to be low, manageable and easy to cash flow when you transition it into a rental.When you move out you will have more money in the bank, stronger assets, and be cash fluid in case you need to make an offer on more investment properties.

If rates drop in the future, refinancing again could lower your payment, but it’s good to make sure the numbers work now just in case.

Before you ask, No, they will not make any back payments.

If you were to refinance property one and pull out another 100k (lets assume a 500k house in tampa that you need 100k for a down payment), you'd be paying 6.5% or so on that 100k. 

Overall sale prices of homes are lower than most areas so that 100-200K can be multiple down payment on investment properties.

I understand the 25k guy .. and the seller carry back folks normally those I see that do that will get the amount they paid for the dirt back in the down payment and the note is pure profit.

Very pretty small house with a great mortgage payment Lessons learned?

You can leverage your HELOC and cash to cover the down payment, the initial rehab draws, and holding costs.