Goodan via Amazon offers its Goodan 1200p 2-Megapixel WiFi Wireless Endoscope for $35.99. Coupon code "KHXMY9YU" cuts that to $28.79. With free shipping, that's the lowest price we could find for such an endoscope by $15. It measures 16.5 feet long and is compatible with iOS, Android, and Windows. Deal ends December 31.

Update: The price has increased to $36.99 before coupon, $29.59 after.