What does Costa want from me?

Hint 1 of 8:

A trade for something valuable.

Hint 2 of 8:

How about for an artifact, maybe from Atlantis?

Hint 3 of 8:

Someone you've probably seen was trying to get an artifact, but wasn't
having too much luck.

Hint 4 of 8:

Professor Heimdall in Iceland was trying to get something out of the ice.

Hint 5 of 8:

The sculpture has an open mouth.  You might want to put a "key" in there,

Hint 6 of 8:

Sophia used the same kind of key in her necklace.

Hint 7 of 8:

You will need to put one of those orichalcum beads in the sculpture.

Hint 8 of 8:

You can get one out of "Sternhart's" temple.  See the question about what
to do in the temple if you haven't found the bead.