Sorry guys but I think that is a scam. I have the original of that picture without the yellow/green side

their's
I think they have just photo shopped it. And while it would be worth alot (if it was actually a real bird and not a phoney pic) I don't think breeders would buy it anyways -
Anthony Olszewski says in a paper on Avian Genetics :
Though of a genetic origin, half siders can not be intentionally bred. Half siders are the result of cytological accidents and are the inverse of twins. The half sider phenotype is not inheritable. A strain of half siders can not be developed.
So breeders don't bother trying to buy them because it can't be reproduced in the birds offspring.
The origional picture is a beautiful bird, waay expensive over here. I would love him to come and live with me
