Ill-gotten gains and success will not sustain." 

Found this in the Arkansas Code:"If the tenant's holdover is a willful violation of the provisions of this chapter or the rental agreement, the landlord may also recover an amount not more than three (3) months periodic rent or twice the actual damages sustained by him or her, whichever is greater and reasonable attorney's fees."

If there aren't any good free solutions, is there a paid service that is recommended for real estate owners?  

I'm looking for help to map out a winable solution (if possible).

Foundation vents aren't the best solution, but you need some kind of air flow down there.

So what I hear your saying @Tony Castronovo is the solution to getting my calls returned is to stand out in my message by letting them know already some of what I'm willing to offer?  

I am trying to come up with the best and “cheapest” possible solution that would make the backyard appealing to sell the property.

If you don't buy, lender has to foreclose, complete the process, organs wait a few more seasons and weather the market and the winter.If you don't buy and the liens pre-existed their mortgage, they will still have to deal with senior encumbrances in order to sell.Nope, you are the solution.

Check for mold on the joists and rafters and clean any with a bleach solution or other cleanser.

Like @Brian Adams, I believe QBs is a good solution.