Well I tend to agree with Audiofeil. That is not to say that the OEM tubes are WAS, just that you can usually, for just a few more dollars, get new production alternatives that will be quite suitible for you. You don't need to spend big bucks on NOS tubes to get a good result when you are using modest components unless you are seeking a very specific result and you can't find a new production tube that will get you there.
Can excellent tubes transcend modest amps?
I am wondering how far a good but not amazing amp design with decent parts such as Antique Sound Lab AQ1003 DT or a Jolida 302B can be improved by putting top notch NOS tubes? In other words, is it worth buying a used $500 integrated and give it an extreme tube make over for $200-400 rather than buying say a PrimaLuna or Cayin in the $800-900 range with its stock tubes?