Brass buttons are not easy to make, and they require considerable skill and
equipment. On the other hand, anyone can make buttons of bone or antler. It
just happens that I have occasion to deal with craft makers of both types
of button.
 
Right now, reindeer antler buttons are selling for exactly the same price
as hand-cast brass coat buttons. However, this reflects modern ideas of
time and work values, and may not reflect eighteenth-century comparative
values.
 
David Babson probably is right about availability. Bone and shell buttons
were made all over the place by cottage craft, but brass founding is a
rather arcane specialty, especially if patterns are involved. There's
plenty of archaeological evidence, however, that pewter casting was not
uncommon in Colonial America.
 
      _____
  ___(_____)                Gotta go. It's spring.
  |Baby the\
  |1969 Land\__===_         Never know when we might need to
  |  ___Rover   ___|o       help a J**p out of the mud.
  |_/ . \______/ . ||
  ___\_/________\_/____________________________________________
  Ned Heite, Camden, DE  http://home.dmv.com/~eheite/index.html