Years ago, I sold off many cels in my collection. Some I regret, others less so...but one that I had been kicking myself for letting go I haven't been able to find in anyone's gallery online, so I was sadly resigned to never seeing it again. But then a sequence mate came up and I was able to get it, ten years later! And--this may or may not be a good thing, depending on your perspective of the cel market in general--the price was less than half what I paid in 2000.

So that said, who else has loved and lost, only to find it (or one like it) again?