How many are there in existence?
No idea, we didn't print them. The studio did. At least 60, probably more. theory11 purchased a lot of 20 at auction.
We’re all cards produced used in movie?
Extremely unlikely. While many cards were likely used, it is almost guaranteed that not all were used. We do not know which were which. What we do know is that these are all authentic and from the movie production.
What’s the value of the card?
Whatever someone is willing for pay for one. They have not sold before, so value is completely unknown.