Let me guess: is it a literal translation of the (very)
Spanish expression "me ha costado un huevo"? We say that in
Spain when something has been extremely tough to buy or achieve...
Of course, we also say "it cost me a kidney", or "it cost me an eye of the
face" (yes, I'm sure you're wondering where one has eyes other that there, but we do say "un ojo de la cara"!).
Regards,
Ignasi