So everyone should test every single thing they buy first? And to disregard any existing testing done or the sources rep in regards to testing and feedback so far?
I mean, unrealistic isn't even the word for that. Would it be the best way to know if it's what I bought and on the label? Yes but you think everyone has the money to test EVERYTHING. Have you looked through the lab testing section lately, hardly no one tests nowadays.
At the end of the day people take risks buying from sources. If I didn't trust any source enough that I had to test everything I buy, I'd just homebrew. Which Is what I'm going to say you do.