Well my friend you snooze you lose! It's happened to me there too.
I've been acquainted with this store owner and store since 1984 when I first got my driver's license. Some of the best bargains of my (music collecting) life found there. Probably the best single day was around 1989-90 or so? My brother was in there in the morning (I was working for some extra $$, it was a Saturday) and said the owner had a bunch of records I might like "Sun Ra and some other stuff". Of course I flew over there. I found around 25 original mint Byg/Actuel titles, all of the Sun Ra on ABC impulse stuff and a dozen or so rarities (Shepp, Bill Dixon, Cherry). I got 45 or so lps for $300. A fortune for me then, but well worth the price at most any given point in time. What pains me the most is that all the Sun Ra Saturn stuff had been there just a few hours earlier. And who knows what else....