I make much more money buying the fixer upper (abandoned, condemned, unwanted) properties for a song and paying cash.

Cash for keys, while unpleasant from a moral standpoint, is often the better choice from a cost benefit analysis standpoint.

And unpleasant. 

Although during an audit, a cross auditor with an unpleasant attitude, or who for some reason dislikes the client, or is just having a bad day might disallow it- causing either a fine or going to court making the client pay for that (And no one wants to be a test case $$$$$$).

While these companies can offer convenience, it's crucial to vet them thoroughly to avoid any unpleasant surprises like excessive fees. 

It is unpleasant enough that I don't want to expose myself to that again. 

Pledging your home and other assets to be able to increase your holdings, from what I've seen can lead to a very unpleasant situation.2) ....why some people become financially free, while the majority of the population is living paycheck to paycheck I've never met anyone who is financially free, that was not a trust fund baby.

The main tenant called me to demand that I remove the unwanted guest because he would not leave.

It has been an extremely unpleasant transaction thus far... boy do I have stories... 

You'll also likely want to make sure that your parents' estate plan is in order and doesn't create an unwanted tax situation after a spouse dies.