I haven't had that happen with cards in a long time. So much of the stuff is so well known and there's a lot of pricing info available, so the deals aren't all that common. I have picked up ungraded cards that did very well but I suppose didn't do well because of bad scans or a less than great listing.
Now in my other hobbies.........
Stamps - The area I collect has a lot of varieties that are worth a LOT more than the normal version. But most dealers can't be bothered to learn what to look for. So I've gotten a lot of BIN deals where I paid a reasonable or even high price for what the normal stamp is, but a silly price for the variety- Like 2250 catalog for 18.50 with free shipping.
Most are more in the range of 10% of catalog instead of the usual price around 50%
Or similarly mislisted stuff with really bad auction planning. Rare variety not mentioned but the auction is listed on Ebay UK, with a seller in Norway who decides to end it at 9AM EST Easter Sunday? Yep, I'm all over that one.
But learning about the varieties took years and a membership in a national club whose magazine published a series of articles on the plate varieties. So Loads of time spent gaining the knowledge.
In the old bicycle stuff the info just isn't out there. And lots of people list stuff with
really bad pictures.
Even now I'm often the only bidder on some really great stuff.
Helmets from the national team in the 80's. Really just fiberglass shells with a chin strap. I've found a set of 4 from 1983 one from maybe 85 and another from 86 or 87. All race worn, some with the riders name written inside. Nobody bid on them but me. (Maybe proof I'm just crazy?
)
Mid 90's time trial bike without brand decals. Listing claimed it was ridden by one famous rider AND a then current star in the us who was expected to race in Europe soonish. Of course a nonsense story, she was smaller and he was larger and there was no proof at all. Took a chance on it at a price that I'd be happy even of it was just that model bike (Not a common bike and while it was missing parts most of the really special stuff was still there) When it came, the shipping label showed the US pro rider as the shipper, and the seatpost has both their names scratched into it. Plus I found out they were on the same team.
So if the seller won't do the research I don't feel bad about getting a deal.
I have pointed stuff out to dealers I like in all hobbies. At one point even not bidding on stuff at an auction where nearly everyone left before the last hundred or so items because of a snowstorm. Min bid was $10 on almost everything and there were some great deals to be had but I just stuck to the handful I really wanted. They put the stuff in the next auction and did very well so it worked out.
Steve B