Since you've been renting it, you need to take a serious look at what (if any) rehab work would need to be done to make it market ready and weight the pros and cons of putting in that work vs lowering your ask.

4 units and under for appraisal they go by the comparable sales approach not the NOI and cap rate.5 units and up for appraisal the most weight is given to the income approach.Residential loans of 4 units and under and commercial loan of 5 units plus are totally different in lending and regulations and criteria for funding.NOI is (net operating income) and this is what is left over after expenses but before the mortgage.

You have several heavy weights in this thread giving much better advice than I could probably ever hope to.However I have a very simplistic mindset and sometimes look at things different and maybe my thoughts will strike a chord.- Always plan for the S*** Hits the fan scenario- What happens if the owner dies?

I could see the fungus in the black mold and the new lighter color fungus spreading down the beams.  

We typically don't put a lot of weight in the pro forma material, seller/selling broker typically paint the best picture possible.

@Jay Ingram Not sure if you found the answers you were looking for but I would check with your local extension office for current cash rent (lease) rates, as well as historic yields for land in the area you are looking. 50 acres isn't a lot of land where I come from but it likely carries more weight in Kentucky.

That being said your purpose for the building is how you should evaluate it with some weight given to your exit strategy.

Holding a special broker/agent only open house is another good idea, let them know there is free coffee/wine/food and it helps get a better turn out.Also, have a mortgage broker ready to work with anyone that wanders in...a good mortgage broker in this case is worth their weight in gold. 

Your threats about repercussions and reporting to credit bureaus really carry little weight.

Everything on the first page, and especially the top half, carries more weight - the rest is just application of the law of diminishing returns