Companies generally "resell" products such as essential oils. They buy in barrels and then attempt to make a 50,000% profit like Northern Botanical did years ago with super strength oregano oil that was 10% oregano and 90% olive oil.
You would have to locate manufactures of essential oils and they normally are going to want to sale by the barrel or at a minimum, several gallons at a time. These companies are going to be in China/Turkey and various small countries where slave/communist labor is very cheap and every thing raised on gov land. Even then, such countries are difficult to trust--for example, I would never trust anything be sold out of Turkey as an essential oil, because many of these companies turn to synthetics and acid methods to fill the demand.
THE LITTLE companies are going to make only a few essential oils such as the mint families that are easy, but the smaller the manufacturer, normally the higher the prices due to labor cost and taxes.
The larger problem is IMPORTING----"if" the manufacture does not use a "generic" oil name for the essential oil, then you have a fair chance it will set in customers for months because they will not know what it is or used for...so they all play that game of "generic" names.
Many of the large bottle essential oils will say many things, most anything to make the sale and in reality, I do not think most have any clue how their oil is made.
For skin use, most are going to be 3% oil and 97% carrier oil. Those selling are scared people are going to let their little children get into the open bottles and have an accident--so they keep the bottles tiny with tiny outlet hole so only 1 drop at a time comes out. Many do say 100% essential oil and odds are they are, but how they are made we have to "trust".
I oike it when they can send you pictures of their crops and their machines, but even then, if your not doing the work your self, you really do not 100% know what the final product is---the same in life with most foods.
I tried turkey, canada, spain, etc. over the past 20 years and ended up with China because they make all the essential oils and herbal products that were used 100 years ago and as their medicines and they oppose synthetic anything. For an example, it can cost $500 in shipping alone for 2 gallons. For the past 5+ years that is the only place I buy from.
They really do not have an English price list, they basically say they make everything--thousands of products...they make 70+ freeze dried juice powders for an example--takes thousands of acres of land and machinery only communist countries can afford. Basically I tell a person what I want and they almost always make it or in some cases, will make just for me. I think I am a "novelty" to them and they find it amusing that a mom and pop type set up can exist over 20 years..or they think I am larger than I am. They always give me a generic American name as a contact; because they know us uneducated Americans as my self, can barely communicate in 1 language. They have even offered to give assistance in understanding the 3 fields of human health as herbs apply, but we are too old to start with that, in america it is hard to sale 1 product successfully alone foreign products. I find that internet customers are drastically dropping off every year as they lack interest in such things.
I do not know any american company that resales essential oils that I would be interested in buying from--your best to buy as direct as possible, otherwise your just paying the middleman over and over. We have never had much success "reselling" products, because everything including myself, always wants to buy from the maker and not the middleman---so the only thing that has ever worked for us is what is unique to us....we barely sale any essential oils and only have ever listed oregano oil. I have a huge collection that I play with and as well use, but have not tried to sale. Selling pure essential oils has to be a strict adult use only product and that makes it tough.
I have not gotten anyone to answer me on the subject of DO THEY MAKE A TEST KIT for essential oils---so I am assuming there is no such thing outside of the labs.