I wonder if any are copies?
This is currently Ornela Desna's pattern number 27889 00 165.
A very high proportion of these will be not original.
By that I mean, they will be from the original moulds, but not produced by Schlevogt per se.
This particular item is still currently in production, and has been, throughout most of the period since WWII.
The zebra is still being carried in the Ornela-Desna "Classics" catalogue. This is probably why you will find such a great variety of prices.
An original, labelled, Schlevogt-produced item, may reasonably be expected to command rather more than a Jablonecke Sklo, or Ornela Desna produced item.