How to Identify High-Quality PMK Powder Online ?

To evaluate the value of a chemical, there are two steps:
(1) Purity
For example: If our purity is HPLC>99.0%, $150/kg, it means that when you buy 1kg of "powder," the effective substance content is more than 990g. The analysis result must come from professional instruments.
(2) Value
As mentioned above, if our product is HPLC>99.0%, $150/kg.
If someone buys 1kg from us, dilutes or mixes it, they then have 2kg of pure white powder. Their price is $100/kg. Who is cheaper?
If someone insists on selling a $200 value product to you for $100 (or another unreasonable price), how can we stop this behavior? We can only say that if you are cheated this time, please don't forget our company and sincere words next time!