With over 50 years of collecting I have plenty of "just missed it" stories! I attend a lot of great collector gun shows, and have seen something I really wanted, but someone was already looking at it. Usually they end up buying it, but occasionally they walk away! On those occasions I snatch it up quickly.
Some years back I was at the big Colorado Gun Collectors show in Denver and walking the aisles looking for something when maybe 30 ft. away I saw a guy setting up late at his table. He pulled out an old duplex powder measure that I immediately recognized as a Schoyen-Peterson because I have one! But this one had rare polished aluminum hoppers instead of the usual glass bottles mine and most others have! I literally ran those 30 ft. to grab it, but a guy was standing at the table as it was set down, and picked it up! I waited and watched as the guy asked how much the seller wanted, and heard the seller say $250! I prayed the guy would pass, but he knew what it was and bought it quickly! When he walked away I stopped him and asked if he wanted to make a lot of money on his purchase, but he smiled and said he didn't want to sell it. I offered him much more than he paid, but he declined.
That has to be one of my biggest heart breaks to be so close to something that rare and miss it by seconds, and 30 ft.!