Let me start off by saying that I have been collecting Lionel postwar for about 42 years. Things haven't changed much in that time as far as expectations of sellers go. Most stuff, given the condition that it is in, is vastly overrated and overpriced. The term "mint" is still used excessively on almost ALL auction and websites. Most of the "mint" stuff has long ago been snapped up by the most discriminating of collectors.
I liken the model train sales to those of the real estate industry.........although there is a vast difference in pricing, the principle is still the same.......pull a figure out of a hat, throw it "out there" and see who goes for it.
Invariably, somebody will think it's a steal and pay the asking price, where the majority of people think the price is insane, and shake their heads at the prospect of something selling for THAT asking price.
Then, as now, people try to recover the extreme price they have paid, PLUS a markup. That is still happening today. It's been discussed a thousand times before. The bubble continues, in both the train AND real estate markets......witness some of the specialty auction results and the insane property sale results. (Here in Canada, that is showing up in the Toronto and Vancouver housing markets)
When it will end, nobody seems to know.
There are going to be some train collectors that will say that the market is down....well, for the high-quality postwar items it definitely is NOT...the prices just keep climbing and the buyers just keep on buying.