https://home.woot.com/offers/healthsmart-500ml-essential-oil-diffuser-13?ref=w_ngh_mc_itm_is_1_tl HealthSmart Aromatherapy Cool Mist Oil Diffuser & Humidifier w/ 500ml Tank (40-500-190) on sale for $6.99. Shipping is free for Amazon Prime Members (must log in with your Amazon account and select a shipping address in order for Woot to apply free shipping) or is otherwise $6 per order.