If demand was going up and up as you say, and the supply was still limited as a result of them laying small clutches and being picky breeders, Economics 101 tells you that the prices would absolutely not decrease.
There absolutely is such a thing as a back door deal. When advertised prices are always 50-100% higher than what they are actually selling for, speculation starts to become a huge factor in what happens to the price. All of those back door deals got around and everyone began to think, "well, if I just wait a year, I can buy it for half." With everyone thinking that and no one buying, its almost a self-fulfilling prophecy because that causes the demand to decrease, with the prices following right behind it.
Think about it, why should I buy a pied now for 2500 when I can wait 2 years or so when they are at or under 1000? Those kinds of statements get into everyone's heads and that kind of speculation truly does affect the market.