lots of opportunities to find easy win-win
finding out what the salesmen incentives are and working with them can lead to a good outcome
obviously not worth it for smaller ticket stuff
Being able to serve yourself and figure out if there's any fit removes friction. Spending an hour on an initial sales call to find out that information isn't optimal.
As he's said, when he's desperate, he will do more work. And he is willing to do calls when it makes sense, but expects them to be efficient and expects to be able to qualify the vendor.