I-Venstar FBA Amazon has a shockproof Venstar Bluetooth 4.0 Speaker with built in Mic, 2x5 watt speakers, an aluminum case, and 1800mah battery for $35.99 after using coupon code 6LP3YYEH at checkout. No sales tax was applied for me.
Shipping is free with Prime or Super Saver Shipping
N.B. This looks like a solid deal for one of the top selling Bluetooth speakers on Amazon and most people won't have to pay sales tax. It also arguably beats this dealfrom a few weeks ago with a cheaper price even though it is not waterproof.