I can see a few valid reasons that would make it the rational decision in some cases, such as reduction of complexity---when an individual gets enough money that they don't mind paying a high premium in opportunity cost for perceived comfort or simplicity. 

Prices might be flattening out lately as interest rates rise and we're seeing listing stay on the market long and more price reductions than before.

I just make sure to get a fat deposit.

One of those big fat tax guides with an index at the library or bookstore, Lassiters, etc might point you in the right direction.

We also have a separate emergency fund for ourselves which includes 6 months PITI + 6 months maintenance (we have a coop for primary residence) + 6 months spending money (with no lifestyle reduction).

12- Sell and CelebrateNegotiate the sales price, go to the closing, and collect your big fat check :).

Buying/selling notes is a good business, but it's important to be the first position unless you've got a fat wallet.

If you have to come back after the fact and get a reduction you can.  

In terms of home appraisal, what if the appraised value comes out to be lower but the seller agrees to the full price reduction?

The the last phase, little to no acquisition, little to no new debt, jettison under performing properties, paying off debt, keeping the cream of the crop properties and living off the fat of the land.6.