He offered to take on the lawsuit for a small fee plus 25% of any monies awarded.

You award me the bid and have essentially bought me a man lift.

Tenant moved and left keys but it voided the monetary judgement they had and the judge made them file a new claim for the damages they had already been awarded. 

What if an award against you is larger than the amount of insurance coverage you have?  

you also know how hard it is to get the judge to award late fees.The answer is do better screening. if you need a late fee to make the rental pay you goofed in your due dillegance. 

Judges won't award you late fees owed but will award you past due rent. 

Possibly more if you are needing to put a large earnest deposit down to get awarded a deal.But back to your question, shop around.  

What I have seen is a seller suing a buyer who failed to perform as agreed for damages resulting in a foreclosure (I made the underlying secondary market loan) destroying the seller's credit and the seller was granted an award greater than twice the amount of the sale, a little over 200k!

Breech of sale lawsuits are extremely rare and courts even more rarely award anything since the seller is usually not out anything, i.e. they still have the property and can sell it to someone else just as easy.

There's no guarantee the judge will award you anything even if you win the case.