There was a thread one one of the domain forums a few years ago (less than 5) where someone asked if anybody had ever LOST money on a domain name. People jumped in and said: 'don't be silly', as if to say that domain name values only go up (that is called a market top, my friends). Well, asset prices can change pretty fast. The downfall was allowing scammers to run wild on all forums.
The other thing that brought about the collapse was that new domain investors were victimized by old pros just to make a buck. The old guard would sell them .mobi, .co, and anything else they could dream up. They were lots of fake sales published for 6 figure amounts for names in extensions that were worthless. I am talking names that are worth as close to zero being publicized as having sold for 100K plus. This would bring in all of the money grubbers on both sides as they traded crap names worth zero in scam extensions back and forth until everyone was broke.
I told almost everybody that 99 percent of domain names are worth zero. Nobody listened. I turned out to be right, as I expected. The party is OVER, but there are decent names out there to be had. Most sellers are still in Fantasyland about their asking prices. They will tell you that they had an offer for 5K on the name during the peak, so they can't sell it below that. I just laugh. That name that they were offered 5K for might not be able to draw a $100 bid here. The highest bid you ever had years ago does not set the bar for the what it is worth....lol.
There are people right now with hundreds, or even thousands of names, that they believe are worth hundreds of thousands, or even millions of dollars. They don't know how bad they have it. If they tried to sell those names in an open market setting many of these people would get less than 5 percent of what they expect (they would be lucky to get even close to 5 percent of what they think the names are worth).