I would check Zillow, realtor, Redfin, trulia etc for recently sold properties that match up well with the subject property.Speaking with the seller or seller's agent could reveal some things but its too obvious to ask "whats wrong with this place?"

The seller could argue that a visual inspection would have revealed the catch basin full of silt, but that would not necessarily support their failure to disclose the problem prior to the sale. 

In addition to this, as I said, I would be willing to contribute work/time to the broker's business, but I don't aspire to be a full-time agent.Even so, your response as well as Charlie's, reveal some things that were not obvious to me before... 

Mostly, having a long conversation with the husband and a separate one with here could be very revealing.

Deidron Clouden,A casual conversation with the seller can be very revealing without the appearance of being "nosy".

What part of the market cycle is this demand (rising prices rents reveal cycles).

@Sami Gren I don't remember the brand it may have been trafficmaster but like I said it was 5 years ago, they had a paper backing that you pulled off to reveal the adhesive. 

In selling property they own, or in which they have any interest, REALTORS® shall reveal their ownership or interest in writing to the purchaser or the purchaser’s representative.

@Kareem Aaron not from your area, but all of the research that I completed reveals there is no statute on prepaid rent.

A few days later I spoke with property manager who revealed BOTH properties had leaky roofs and water damage, yet sellers disclosed this on only one property.