The first sale was not an open market sale. It may have been a FSBO( not uncommon for buyers unrepresented to overpay) or a related party sale with something going on.
The 2nd sale was 125 sq ft smaller and very dated. It looked in no better than fair condition. It was an REO that fell out of escrow and when that happens its not unusual for them to sell for less the 2nd tikme around as the intial frenzy has died down.
The 3rd sale is a trust sale. Its dated also but the pictures looked adorable. Trust sales are generally listed low and the market will determine price on it. It will be interesting to see what happens and it should sell quickly though it has a slower time of year to contend with.
The interesting thing is none of these are traditional open market sales so what happens next is very unpredictable. Even if it sells for 465K its impossible and probably inaccurate to say the next one will have to be 10% lower. It is actually a pretty unique situation subject to many different interpretations next time around.