When it comes to essential oils the phrase that you get what you pay for rings very true. I myself should know better than to buy some discount essential oils, but on a couple of occassions I have been temped and both times I got a dud deal. Prome examples are things like Rose oil for $25 for 15ml or Sandalwood oil at $10 for 15ml. There is plenty of adulterated Rose oil and absolutes available but the smell from these is around 10% of what real Rose oil should smell like. The same with Sandalwood, Mysore Sandalwood is expensive and so is Australian Sandalwood but the Mysore sandalwood from India is these days most likely cut with other oils because the Indians have cut down most of the Sandalwood trees, These trees need to be around 30 years old to get good quality oil. In Australia it is better managed and the Sandalwood oil from Western Australia is top quality. There are a lot of essential oil sellers on Ebay and it is hard to know who is selling the good oil and who is selling the adulterated stuff. I recently bought some product from a seller in the USA who had a 8000+ positive feedback rating and only 22 negatives, I thought that his products would be good but when I compared them to my lab standard oils I was very disappointed. This proves to me one thing and that is the general public have no idea on what they are buying. So when it comes to Essential oils buy from trusted sources that bulk buy from the big botanical supply houses. If you are to buy a lot of different oils ask for samples first, if they will not supply samples at cost then do not trust them. Another good way of testing oils is to buy small 5ml bottles from Health shops that are distributed by the larger botanical companies, these are usually Lab tested by themselves and of a very high standard. Use these as comparison oil samples. It is hard buying essential oils on the net but remember if its very cheap so will be the quality.