Electronic Express via eBay offers the Open-Box Fugoo Style Rugged Bluetooth Waterproof Speaker for $49.99. Apply coupon code "PSHOPEARLY" and checkout via PayPal to drop the price to $39.99. With free shipping, that's the lowest price we could find by $50. It features a frequency response of 60Hz to 20kHz, two 28mm neodymium tweeters, built-in microphone, and water resistance up to three feet. Deal ends November 20.

Note: The coupon can be used up to two times per PayPal account.