If you're dealing with businesses on a wholesale level, even a small performance part place should be able identify who they bought from so they can go back through the supply chain and see who a bad actor is. That's why you should stick with reputable vendors. If a company buys from whomever they can get a good deal from, and all the parts go on the same shelf with no tracking, then you're open to get screwed by counterfeits. ISO9000 and other bureaucracy is expensive, but it has a purpose.
I'm a cheap basturd, but I always buy from reputable vendors, especially for critical stuff like valvesprings.