Wild caught croc monitors in the 4' to 5' range are usually what you see for sale,
if you have small ones, like 24" to 36", they are more desirable and people will pay more, but it hardly matters because they grow so friggin fast!
If you have a very large croc, like 8' plus, I would imagine you can get a really good buck for that also, a couple thousand , im guessing.