ER, you’ve made my point for me. If “zillow” values are actually correct, the old listings the on three links you just posted are now almost equal to (or beyond) “millenium boom prices,” regardless of the amount of MR still owed on them. They went back up because their micromarket shot up in price in the ensuing couple of years. This (partially) explains the amounts of your recent unsolicited offers.
A property being sold way below market as a short sale also has a tendency to shoot up in value after purchased/cleaned up a little.
Congrats, ER! MR paid off or not, you apparently purchased in an area of high demand. It will be interesting to see if this level of demand keeps up if the majority of properties begin listing (and selling) for OVER $1.5M and stay there.