In virtually any situation for a US citizen you do NOT want to hold real estate in a corp such as the S Corps you have in place.

I'm not a US citizen.

If the market rent is 550 and he’s paying 300 then hopefully you can find something simple such as the Zillow rentdometer(proof for the average citizen)that shows comps going somewhere between $400 and $700.

However, I think most citizens lack the training for military ops.

How have you overcome any financing issues as a non US citizen or resident?

Do you have to come up with money out of your own pocket ever to cover the loan, can you get a loan in Mexico without being a citizen, and what is the size of your condo? 

I was a mayoral appointed board commissioner for a senior citizens housing facility for 3 years and then a Florida foreclosure attorney for 2 years.Right now I'm in the early stages of my journey to become a real estate investor.

Because it was a nicer, more affluent area there was much less crime, and many times, we as citizens had to worry far more about traffic tickets as opposed to getting robbed at gunpoint, or my car our home broken into.

. - professional, with our logo etc.We send mostly postcards to the big pools like absentees, sr. citizens, etc.  

Citizens, Probates, etc.3) Signage - bandit signs, billboards, digital boards, event sponsorships, etc.Surprisingly, you can get some leads from Craigslist as well.If I had only $1K per month to spend on marketing, I do an AdWords account with a $33 per day budget.