If you are interested in making your own thunder gourd, I have a tutorial available for $25 which includes shipping, one spring, two synthetic drumhead membranes, and a 3 page detailed instruction explaining the process and a list of all supplies needed to complete your own thunder gourd.
Option 1: Each additional spring is $5. On orders of 20+ springs they are $4 each. On orders of 100+ springs they are $3.50 each. This spring is 100% ready to be used, no stretching required or anything else.
Options 2: $3.50 for each spring. On orders of 20 or more springs they are $3.00 each. The only difference between this spring and the other one is that it does not have a clay bead baked on the end of the spring. Again, NO STRETCHING REQUIRED FOR THE SPRING!!!!!
Each 6x6 inch square drum-head membrane is $1 each, 8x8 inch thick sheet is $2, a 2x2 foot thick sheet for $13 and a 2x4 foot sheet for $24 which is thicker, stronger and more durable. Shipping normally runs between $6 and $15 depending on the quantity ordered.
To place an order you can go to www.thundergourds.com , email me and let me know what all you are interested in, I can give you a total and process the payment over the phone. I can process all types of credit card payment. My email is firstname.lastname@example.org, my phone number is 208-914-1776, and my address is 2719 S. Almond Ct. Nampa, ID 83686.