It's all about the location, you might be able to buy a cheap house, but if it's in an area with nothing but other cheap houses and in an area that is "not desirable" you're not going to make much money on it, either in improvements or rent.

@Mike Klarman:  Can you quantify what "not cheap" is? 

It's better to pay more, knowing you have something secured versus cheaping out and not even closing. 

As I’m sure you know, Las Vegas is SUPER cheap compared to most of California, Miami, or NYC.

Buying well built properties - or cheap enough that they fully redid them3.

is it in A cheap city that has vacant properties selling for far lower than turnkey rentals?

For a 1-4 unit in a cheaper cash-flowing market a the costs to refinance are not cheap relative to the equity being pulled out in many/most cases. 

I ask for a down payment even if its under 2,500 this is because the customer will often times run out of money once they pay everyone else then hire one of these other guys to finish up for cheap.

I am going to be the contrarian on this subject.. 1. the pre license course is valuable as it teach's the vocabulary of real estate and the basic laws of your state.. its dirt cheap and one of the better ways to build your foundation. 2.

They are not cheap by any means (expect double digit interest rates) but they are available.