This has been the issue for me in the past and it is amazing how much condensation develops in just one day.  

**here is the condensed version below see in between the dashes, for the longer version please read after dashes===============================================3.** Now where it's interesting is that the property has officially sold.

I'm brand new can my fellow pros give me supersweet and sexy condensed tips on best way to get comps?  

For example, a cold water supply pipe above that vent might have warm moist bathroom air from the downstairs shower/bath migrate and condense on the cold surface causing a drip drop minor leak.

This can be caused by condensation.

Kind a misleading metric to chase, like mentioned in almost every area it's going to come down to a more condensed neighborhood at best, at worst it'll be block by block.neighborhoodscout is a interesting website, haven't used them in a long time (I think it used to be free) but they might be of use to you.

It's so bad we have to put AC condensers on the roof  or hang them on side second story or they walk off.

Here is the horror of this:We were set to close 11/20/2018 (45-days from contract)...the appraiser came out around a week prior to walk-thru the unoccupied unit to get things moving...good deal...it passes with flying colors and he moves to the outside…no mention of any issues and he gets comps in order…the contract price is good based on comps, so we just need to walk through the occupied unit then we’re clear to close..He gets to the occupied unit...and he notices a small bit of water on the basement floor near the furnace (Image attached)...maybe the condensate line is dripping a bit, no big deal, we’ve already agreed to a $3,000 post inspection concession for repairs, so the buyers can fix this...the next day the lender decides there is peeling paint around some of the windows...three days prior to close...not in the appraisers report!...

A postcard will be either identical to what you would put in a yellow letter, or a more condensed version of it.2.

It sound like it is cooling, just not very well,   Could be a dirty evaporator coil, a dirty condenser coil, dirty filters, or it might need Freon.