the ones I have bought in the past have been on a wide range , my first one was around 45 from UK,then I found the complete twins in Mexico with Backcard loose within a lot of g2s , It was a lot of the twin sets , they came up around 12.50 per pony if split even within the lot
then I found another loose one from France for 12 Euros shipped
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I saw a pair listed some years ago they had their skirts and they were on ebay for 170 dllrs
for 1 of them should be from 15 to 50 I would say , maybe with pictures they can be a better price check ,since the head is glued , that means the head was cut off at some time ,so In my opinion it would go for the lower side of the price range.