...Spoken like a person who's never coded anything meaningful or serious, if you can't even gauge the complexity and man-hours needed to create (much less port) high-quality packages between programming languages.
Talking about "man-hours" tells me you think of software engineering like an assembly line, which it is not.
There are whole lot of factors that might influence the time needed for such porting; the keyword in my comment is "similar". If the new language is a superset of the original language, minus a few warts, I'm not sure what should take so much time. For one thing, the architectural design of the packages (which probably took most of the original effort) remains the same.