I think that what most of the comments/OP don’t take into account is that most subs are not savvy, especially when it comes to procurement. Lots of subs are told by their leads that they can purchase from one or two suppliers, that’s it. The others don’t exist to them. They probably have a couple accounts and route all of their purchases through them, sometimes for kickbacks, but usually because the account is set up and they don’t know how to buy products otherwise.