Two thousand years ago amber was quite valuable

This was mainly because it was one of the first forms of jewelry, and also because of superstition that it was made by the gods, that sunbeams produced it, and that it brought good fortune to those who wore amber necklaces.

But as fashion trends changed, science disproved things, and people had their heads cut off just as easily with amber earrings as without, people chose other jewelry as a fancy.
However, Amber can still be very, very, very valuable.