I based my Scute price on the damage resistance of the helmet you can craft with them (Turtle Shell). If you already sell any other helmet piece, just multiply that price with the percentage increase/decrease in damage resistance of the Turtle Shell (found on wiki). Divide the result by 5 and you have the Scute price.
See my server's price list for inspiration if you like:
https://sunnyshadowz.wordpress.com/price-list/
