There is absolutely no reason to spend a lot of money on a diffuser. Always look for coupon codes and discount codes too. Both my plant therapy and Edens Garden diffuser were purchased with 15-20% off

Plant Therapy AromaFuse - Run almost nightly with no issues

TaoTronics 300ml This is in my office and I only run it when I am working in there

InnoGear 300ml - This is in our family room and I only run it when we are relaxing in there with family.

Ceramic Ultrasonic Diffuser - Blue Ombre - Run this daily no issues