>>I guess it's best to pay over the odds and assume it's not worth the supplier's time and money to adulterate a product already commanding a high price. Or it

>>I guess it's best to pay over the odds and assume it's not worth the supplier's time and money to adulterate a product already commanding a high price. Or it's the opposite - if you can put £1 worth of oil in a bottle selling for £10, you've made a huge amount of profit. On the other hand how much can you really save on a bottle selling for £2? Yeah economies of scale and all that, but at the end of the day it's probably worth targetting the more expensive product(there's a reason why watch fakers make fake Omegas and Rolexes, and not fake casios(although I'm sure those exist too)).