Error variants are basically a thing of the past. For some reason people saw "Short Saber-Long Tray" and "Full Circle-Half Circle" type figures as interesting to collect for a time, I think mainly because there weren't literally hundreds of thousands of figures circulating around like there are today.
If you like it, that's great. If you are looking for some sort of increased value because the wrong figure is on the card or the item is upside down??? Unfortunately it's likely worth less in that condition.
If anyone wants to chime in, I'm by no means an expert in error variants.