Quote from @Joe Paasch: I have joined this site to gain important incites, discussions and plans to build a successful portfolio.  

Your success is my success.

Here's an article with things to consider when selecting a cost segregation company.

The only other question I would suggest is that you do engage a property management company to review your quad and review your monthly financials.

But, the seller will never close a sale until the buyer releases that claim and withdraws the affidavit because a new buyer's title company will not issue a title policy and the new buyer's mortgage lender will not make a mortgage loan.Its not worth doing in this case but when real money is involved it is pretty effective.

Could you recommend a trustworthy and cost-effective company for this? 

I own 11 properties currently and I have only sold 1 in the past because it was a condo with a fraud HOA company.

Boostly is a great company and the founder is a great guy!

To make the strategy successful, you need to find a property that can be acquired below market value.

Thus, the preREO strategy is to have a court appoint a receiver, which could be a real estate agent or property management company, to repair and rent the property during the foreclosure.