IMHO these are spectacular, but second-best to the Spyder Factory cars, which have an accurate clam reinforcement bit and front firewall/bulkhead, along with the more advanced "high rail" chassis as seen in the Werks cars and later builds like 0090. My guess is plus or minus $200k. I believe it would be about $300-350k to duplicate and probably a year wait.
But on BaT you never know.