The provided details of its history are sketchy. The cross was apparently owned by "Adam Park", a "famous UK horror collector" and writer for a "famous European horror magazine", who received it along with the other crosses/nails from "Robert Kirsch" (or Karsh?). Kirsch, hired by producers Ugo Tucci and Fabrizio de Angelis, was the prop maker who fashioned the crosses for the sequence. The seller also claims to have another cross that was damaged, but the one in this auction is in perfection condition.
Of course, with a non-returnable "Buy It Now" price of about $670US (¥68,000), you'd have to have balls of steel to take such a chance on two bits of wood tacked together. That's probably why it still hasn't sold, even after being re-listed several times over the past few weeks. If definitively proven original, it's certainly something special, despite not appearing exactly screen used. Using Yahoo! Auctions outside of Japan is impossible without a forwarding service like Jauce or Rinkya. Even then, there's a learning curve and all sales are final, even if the item arrives destroyed. So this dubiously "one of a kind" piece will probably remain in Japan for now.