NOS vs used tubes

I've enjoyed my tube gear for sometime now and never paid much attention to it, just enjoyed the music. I've started to listen more carefully and have decided to investigate the finer points of tube ownership. ( which is probably a mistake) I'm interested in doing some "tube rolling". I'm not sure paying a premium for NOS vs good used tubes makes sense. Is there a sonic difference if a used tube tests out to 70-90 % of the new one? Or is it strictly a longevity issue and one gets the extra hours out of the NOS? Is it a matter of hours vs. dollars and NOS buyers chasing something that's not there.

Any thoughts would be appreciated

I have been happy with used tubes. Many are available that are close to NOS. Keep in mind that unless you own a tube tester, you have no way of knowing a tube is really NOS. And some NOS tubes don't test as new because of age.
I buy mostly used tubes from sources that represent the product honestly. If the NOS tube you need is not in high demand there may not be much difference between used and new.

Unfortunately, most of our stereo gear uses the same dozen or so tubes, putting us in competition for dwindling NOS tubes.

Buy used that test good for most needs. If a tube is in a hyper critical situation such as the first stage of a phono, then selected NOS may be worth the premium price.
I have no preferences for new v. used. The only thing I look for is that the tubes are closely matched. A set of "marginal" to "good" tubes that are matched sound a lot better than a set of strong tubes that do not. Also, some tube gear works best with what the manufacturer provides you with. I have tried many a tube ($$$) in my CAT preamp and have always gone back to the batch Ken sent me.
Well said, Albert.
I would suggest contacting Andy Bouwman at He will deliver you some of the most straight-shooting, best-informed, non-BS opinions on the subject.