I've bought tubes from folk that were absolutely garbage.

Hmm, would that be the tubes that were absolutely garbage, or the folk you
bought them from? ;-)

Dan Nelson told me a great story. Once, he had gone through a great number of
tubes, testing each one of them. He put a huge number of bad or very poor
tubes in several boxes and put them out in the garbage. Several days later a
resale shop called him up to see if he was interested in a large number of
tubes. Someone had picked them from his garbage and sold them to the resale
shop.........all garbage.