Normally when a  property is advertised as "cash only" the property is in poor condition and/or the seller wants to reduce contingencies and opts for a cleaner transaction.

It took a long time and renovation to get it back to where it was.This is our first investment property and it’s just gone so poorly.

Your OP sounds like you are more on the cash poor side.Hope these are useful topics to ponder. 

Central America is known for poor quality teak.  

In my opinion, that is a riskier bet because you have to have a big pile of cash for contingencies.  

Sub-to is an army of poor ignorant being lead by a handful of savvy opportunists.

To avoid going through the same poor experience, keep reading.Even if someone gives you a referral here, do NOT make the mistake of assuming that the PMC will meet your expectations, just because they met the expectations of the referral source.In our experience, the #1 mistake owners make when selecting a Property Management Company (PMC) is ASSUMING instead of CONFIRMING.It's often a case of not doing enough research, as they don't know what they don't know!

Sounds like their combined income likely beats your other tenants.Your gut is probably your best bet and you need to go with it. 

Check out our comments on Pissed Consumer for more about this poor excuse for real estate investing software.

@Ricardo Matos Amazing you are finding €5k apartments, are they just in very poor shape, or are they semi-rural?