I always search for alternative sellers. They are more likely to have someone who knows the product. A plumbing supplier will know something about pipes and I have some reason to trust them when they give advantages to their different price levels. I don't need 200 different brands of 1/2 inch pipe connections, I need the 3 different levels of pressure they are rated for, and the choice of material they are made from. They also tend to provide reasonable sorting so that I can find what I need without scrolling for ages.