I've been running searches for "O Gauge" and "O Scale" on eBay for about 5 years now, and for the most part I enjoy seeing what comes back. I've bought a number of things during that time, almost always because there were still bargains to be had in spite of what I considered large-scale overpricing. There have occasionally been unusual things reasonably-priced to add to my collection and I so I purchased.
I think that in general most sellers on eBay have closet dreams of getting rich while simultaneously unloading things that they've accumulated.
However the "dealers" that sell on eBay rarely have items that I'd buy because high pricing seems to be even more important to them. For this reason you often see them having pages and pages of listings that never seem to change, much less shrink. These folks, in my opinion, are very satisfied with showing you their collections. That's what their listings turn out to be -- since they'll gladly hold on to them for years before letting anything go at a more modest, and reasonable, price.
Success with retail sales is based on throughput -- the more you push through, and the faster you sell it, the more money you make. More importantly you don't make anything by holding on to your stuff on principle. Dealers should know this. eBay should push the concept because more frequent transactions mean more money for them.
Lately it seems things have gotten worse. Some of this we can certainly attribute to a renewed interest in hobbies due to the pandemic and it's lock-down. Noticeably higher prices are appearing because demand is up, and items that are priced higher are actually selling. It's good for our hobby that our stuff has gained some value, instead of slowly falling like it had been before COVID-19.
But these post-auction listings on items originally handled by Stout are simply ridiculous. I have the Mercury set mentioned in Daniel's post. I bought it brand new back in 2005 or 2006 and probably paid as much then as the current seller on eBay is asking now.
If you look at this seller's entire roster it appears that this person stands to make at least $35,000 on what probably cost $20k at the auction, at the most. He/She lists most every item as being "rare" when none of them are. This is definitely a get-rich-quick scenario. Normally I'd be pleased that my Mercury and the cars have appreciated in value, but not in this case.
BTW -- Based on the size of his/her collection, and the prices he/she is asking, you'd think he/she'd have more professional pictures. They're not detailed enough for the discriminating buyer to see what they're getting for their money. They're taken with a flash so the few colors that are present are completely washed out, and that beautiful gray comes off as much darker that it really is. This is an amateur trying to convince people that he/she's a professional.
If we wait a while, and probably not too long at that, things will return to where they were on eBay before the pandemic -- generally too high but not unexpected, and with a few bargains thrown in. Patience is a virtue.
M.H.M.