Watch Topline's automated manufacturing video and you can understand how the cost of making a lifter (or anything else) might be less in another country. Not sure if this reflects their current process, but I am sure their investment in custom equipment would have to be spread over a LOT of parts. And the market for old Pontiac parts is probably two levels below "a LOT" in their world.
https://youtu.be/lLx_2UKcjS4