Bob,
Here are two sources:
Elastic Cord - Metallic Elastic Cord - Stretch cords - Stretch Beading Cord - Jelly Cord
Metallic Elastic Cord - Gold - # 10062-22 36 yds $3.39
Sew-Biz Fabrics Webstore - Elastic Shock Cord
#ec-2 1/16" Elastic Cord Per Yard $0.29/yd.
Try doing an internet search on "
metallic elastic cord" rather than "
elastic string", and you may find more sources.