Not every possibly interested party is able to see every possible auction. I have paid a premium on this site when someone picked it up off of ebay for half what I paid. I knew this when I did it and felt no ill feelings towards the seller. I even told him that it essentially was a finder's fee, because he found it and not me.
Also you can't assume the prices are going up across the board on photos. Each auction seems to bring different prices. Some stay close, but others have drastic changes.
For instance this Ruth that sold in 2014 for $1068, then resold this year for $105
https://rmyauctions.com/bids/bidplace?itemid=3433
https://rmyauctions.com/bids/bidplace?itemid=23110
If the buyer this time around keeps seeing posts that say values are going up in photos and sees they bought a photo at 1/10th the price it last sold at in the same venue, would it be unreasonable for them to think they could ask 10x the value this time?