Puritan's Pride cuts up to 50% off a selection of essential oil diffusers. Plus, they take an extra 5% off when you add them to your cart, with prices starting from $7.31 after all discounts. Even better, all orders qualify for free shipping. A couple of best bets: Spa Room Aromafier for $9.50 (pictured, low by $5) Spa Room Mistifier for $33.25 ($17 off)