I don´t think there is any question the boom happened. My sales figures showed a steady upturn month on month from November 2000 until October 2004.
In the final quarter of 2004, like for like figures showed an almost identical rate of decline.
The interesting thing about it all was that the average buyers budgets hardly changed. Even as recent as 2007 (Final quarter) the average buyer in my area was still looking at around 200,000 euros compared to 185,000 in 2001.
My personal opinion is that those agents who took on resale properties at any price and added abnormally large commissions on top created the over inflated property price curve from 2002 right up until last year.
The boom began, from the UK buyer point of view, because the average Spanish property price was about half of its UK counterpart. This meant you could sell a house in the UK and buy similar in Spain and live on the difference.
Now prices on both sides are aligned, hence the need for the cheaper emerging markets. Budgets have still not increased by much over the 7 years.
I think the larger builders of new property identified the boom a year or so later and small to medium size builders a year after that. By the time finance and planning was through they were a little late and this has lead to half sold resorts and over-supply all over Spain.
The credit crunch has so far not fully bitten, the exchange rate however has, hence cancellations and delays in people makeing a decision such as sun-seekers example.
When and if the crunch fully bites, then the real tumble in prices will turn from a looming threat to a deluge, but probably not until the end if the traditional buying season, say around October.
All of the above is my opinion using my own stats experience and instincts. I shall no doubt be proved wrong.