Talk to a bunch of them to multi-source vendors and keep them honest through competition for your business.

But good Multi REO's seem to have slowed to a crawl for various reasons, and many of those same investors have turned towards purchasing the distressed SFH plan with flipping.. making them hard to find, and when you do find them, there's a little bit of competition so the deal may not be as sweet.

I feel that I already have a competitive advantage because along with roofs, my company does full exterior work ranging from decks, siding, windows, custom trim work, ect.

I once heard an analogy of thinking of our goals and achievements as a fraction with the achievements on top (numerator) and goals on the bottom (denominator).  

In broader terms the benefits are Cost Reduction, Improved Operational Efficiency and create competitive advantage.

For rents I use Padmapper and Walkscore to get an idea for what competition might be.

The Portland & SW Washington market is going nuts right now, most people are taking advantage of it, asking outrageous prices.Right now the Hawthorne area is the 5th most competitive neighborhood in the Nation.

There are several that are competitive and have good reliability. 

The Certified contractor deal limits the competition a little, like the asbestos certifications in the 70's and 80's (yes I'm old). 

You can do anything you set your mind to.I was also scared to rent in my current area because there was so much competition.