Best Essential Oils & Diffuser (NOT ABOUT BABY)

I am currently pregnant with baby #2 and after reading about all the chemicals in most candles, wax melts and aerosol sprays, we are moving towards more natural products. I have been googling the best cheaper (like under $30) oil diffusers but there’s sooo many options I’m have not be able to narrow down my search at all really. I need one large enough for an open concept home, but not so big you walk in the room and it’s all you see. I would also like to know if any of you have a favorite brand or type of essential oils you use in the diffuser? I personally like “strong” smells, and will most likely change them out seasonally (Spring - Floral and Citrus, Summer - Fruity, Fall - Woody, Winter - Sweets & Spices). Any recommendations?